You are viewing a plain text version of this content. The canonical link for it is here.
Posted to issues@spark.apache.org by "Lukasz Zukowski (JIRA)" <ji...@apache.org> on 2016/11/17 23:30:58 UTC
[jira] [Resolved] (SPARK-18494) Exception java.util.ConcurrentModificationException when long running JDBC data read

     [ https://issues.apache.org/jira/browse/SPARK-18494?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Lukasz Zukowski resolved SPARK-18494.
-------------------------------------
    Resolution: Won't Fix

Everything is ok.
Cause of this was jdbc driver and fetchmode set to 0

I just set the
p.setProperty("fetchsize","1000")
and add
.repartition(10) before persist and task was finished within 20min on my laptop.


> Exception java.util.ConcurrentModificationException when long running JDBC data read
> ------------------------------------------------------------------------------------
>
>                 Key: SPARK-18494
>                 URL: https://issues.apache.org/jira/browse/SPARK-18494
>             Project: Spark
>          Issue Type: Bug
>    Affects Versions: 2.0.1
>         Environment: 
>            Reporter: Lukasz Zukowski
>            Priority: Critical
>
> When I'm reading data from SQL database via JDBC and I have only one partition with lot of data then always below exception occurred.
> ExecutorLostFailure (executor 0 exited caused by one of the running tasks) Reason: Executor heartbeat timed out after 148561 ms 
> This is a test code but similar on real system causes the same.
> {code:title=JdbcTest.java|borderStyle=solid}
> def main(args: Array[String]): Unit = {
>     val c = new SparkConf
>     val w = SparkSession.builder().appName("jdbctest").master("spark://192.168.100.105:7077")
>         .config("spark.serializer","org.apache.spark.serializer.KryoSerializer")
>       .getOrCreate();
>     w.sparkContext.addJar(SparkContext.jarOfClass(classOf[org.postgresql.Driver]).get)
>     val p = new Properties
>     p.setProperty("user","postgres")
>     val df = w.read.option("driver","org.postgresql.Driver")
>       .jdbc("jdbc:postgresql://192.168.100.105:5432/postgres"
>         ,"(select\n\td,\n\t'aaaaaaaaaa' id,\n\t2\nfrom\n\tgenerate_series(\n\t\t1,\n\t\t2000000000\n\t) d) a",p).persist(StorageLevels.MEMORY_AND_DISK_SER)
>     df.show()
>   }
> {code}
> Below Stack trace from Executor:
> 16/11/17 21:04:15 INFO executor.CoarseGrainedExecutorBackend: Started daemon with process name: 83@worker
> 16/11/17 21:04:15 INFO util.SignalUtils: Registered signal handler for TERM
> 16/11/17 21:04:15 INFO util.SignalUtils: Registered signal handler for HUP
> 16/11/17 21:04:15 INFO util.SignalUtils: Registered signal handler for INT
> 16/11/17 21:04:15 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
> 16/11/17 21:04:15 INFO spark.SecurityManager: Changing view acls to: root,zulk
> 16/11/17 21:04:15 INFO spark.SecurityManager: Changing modify acls to: root,zulk
> 16/11/17 21:04:15 INFO spark.SecurityManager: Changing view acls groups to: 
> 16/11/17 21:04:15 INFO spark.SecurityManager: Changing modify acls groups to: 
> 16/11/17 21:04:15 INFO spark.SecurityManager: SecurityManager: authentication disabled; ui acls disabled; users  with view permissions: Set(root, zulk); groups with view permissions: Set(); users  with modify permissions: Set(root, zulk); groups with modify permissions: Set()
> 16/11/17 21:04:16 INFO client.TransportClientFactory: Successfully created connection to /192.168.100.105:35847 after 51 ms (0 ms spent in bootstraps)
> 16/11/17 21:04:16 INFO spark.SecurityManager: Changing view acls to: root,zulk
> 16/11/17 21:04:16 INFO spark.SecurityManager: Changing modify acls to: root,zulk
> 16/11/17 21:04:16 INFO spark.SecurityManager: Changing view acls groups to: 
> 16/11/17 21:04:16 INFO spark.SecurityManager: Changing modify acls groups to: 
> 16/11/17 21:04:16 INFO spark.SecurityManager: SecurityManager: authentication disabled; ui acls disabled; users  with view permissions: Set(root, zulk); groups with view permissions: Set(); users  with modify permissions: Set(root, zulk); groups with modify permissions: Set()
> 16/11/17 21:04:16 INFO client.TransportClientFactory: Successfully created connection to /192.168.100.105:35847 after 1 ms (0 ms spent in bootstraps)
> 16/11/17 21:04:16 INFO storage.DiskBlockManager: Created local directory at /tmp/spark-03af7c89-1082-42c9-85cb-4e340ea5f7c4/executor-3249da99-0293-43a4-9201-4236a7410236/blockmgr-117da12f-c98d-4b61-a4da-3b3df09e1f40
> 16/11/17 21:04:16 INFO memory.MemoryStore: MemoryStore started with capacity 366.3 MB
> 16/11/17 21:04:16 INFO executor.CoarseGrainedExecutorBackend: Connecting to driver: spark://CoarseGrainedScheduler@192.168.100.105:35847
> 16/11/17 21:04:16 INFO worker.WorkerWatcher: Connecting to worker spark://Worker@172.17.0.3:8881
> 16/11/17 21:04:16 INFO client.TransportClientFactory: Successfully created connection to /172.17.0.3:8881 after 1 ms (0 ms spent in bootstraps)
> 16/11/17 21:04:16 INFO worker.WorkerWatcher: Successfully connected to spark://Worker@172.17.0.3:8881
> 16/11/17 21:04:16 INFO executor.CoarseGrainedExecutorBackend: Successfully registered with driver
> 16/11/17 21:04:16 INFO executor.Executor: Starting executor ID 0 on host 172.17.0.3
> 16/11/17 21:04:16 INFO util.Utils: Successfully started service 'org.apache.spark.network.netty.NettyBlockTransferService' on port 42589.
> 16/11/17 21:04:16 INFO netty.NettyBlockTransferService: Server created on 172.17.0.3:42589
> 16/11/17 21:04:16 INFO storage.BlockManagerMaster: Registering BlockManager BlockManagerId(0, 172.17.0.3, 42589)
> 16/11/17 21:04:16 INFO storage.BlockManagerMaster: Registered BlockManager BlockManagerId(0, 172.17.0.3, 42589)
> 16/11/17 21:04:17 INFO executor.CoarseGrainedExecutorBackend: Got assigned task 0
> 16/11/17 21:04:17 INFO executor.Executor: Running task 0.0 in stage 0.0 (TID 0)
> 16/11/17 21:04:17 INFO executor.Executor: Fetching spark://192.168.100.105:35847/jars/postgresql-9.4.1212.jar with timestamp 1479416655063
> 16/11/17 21:04:17 INFO client.TransportClientFactory: Successfully created connection to /192.168.100.105:35847 after 0 ms (0 ms spent in bootstraps)
> 16/11/17 21:04:17 INFO util.Utils: Fetching spark://192.168.100.105:35847/jars/postgresql-9.4.1212.jar to /tmp/spark-03af7c89-1082-42c9-85cb-4e340ea5f7c4/executor-3249da99-0293-43a4-9201-4236a7410236/spark-9ce4cb44-f055-4a98-8cfa-d35ac503f66a/fetchFileTemp6548238816410526401.tmp
> 16/11/17 21:04:17 INFO util.Utils: Copying /tmp/spark-03af7c89-1082-42c9-85cb-4e340ea5f7c4/executor-3249da99-0293-43a4-9201-4236a7410236/spark-9ce4cb44-f055-4a98-8cfa-d35ac503f66a/-14710252291479416655063_cache to /usr/spark-2.0.1/work/app-20161117210414-0007/0/./postgresql-9.4.1212.jar
> 16/11/17 21:04:17 INFO executor.Executor: Adding file:/usr/spark-2.0.1/work/app-20161117210414-0007/0/./postgresql-9.4.1212.jar to class loader
> 16/11/17 21:04:17 INFO broadcast.TorrentBroadcast: Started reading broadcast variable 0
> 16/11/17 21:04:17 INFO client.TransportClientFactory: Successfully created connection to /192.168.100.105:39669 after 0 ms (0 ms spent in bootstraps)
> 16/11/17 21:04:18 INFO memory.MemoryStore: Block broadcast_0_piece0 stored as bytes in memory (estimated size 6.2 KB, free 366.3 MB)
> 16/11/17 21:04:18 INFO broadcast.TorrentBroadcast: Reading broadcast variable 0 took 80 ms
> 16/11/17 21:04:18 INFO memory.MemoryStore: Block broadcast_0 stored as values in memory (estimated size 12.7 KB, free 366.3 MB)
> 16/11/17 21:06:57 INFO codegen.CodeGenerator: Code generated in 251.022749 ms
> 16/11/17 21:07:03 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@6e435e9a,BlockManagerId(0, 172.17.0.3, 42589))] in 1 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:07:43 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@92c4310,BlockManagerId(0, 172.17.0.3, 42589))] in 1 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:07:53 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@4c9d35ac,BlockManagerId(0, 172.17.0.3, 42589))] in 1 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:07:56 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@4c9d35ac,BlockManagerId(0, 172.17.0.3, 42589))] in 2 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:07:59 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@4c9d35ac,BlockManagerId(0, 172.17.0.3, 42589))] in 3 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:07:59 WARN executor.Executor: Issue communicating with driver in heartbeater
> org.apache.spark.SparkException: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@4c9d35ac,BlockManagerId(0, 172.17.0.3, 42589))]
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:119)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	... 13 more
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:08:03 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@2a069e29,BlockManagerId(0, 172.17.0.3, 42589))] in 1 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:08:06 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@2a069e29,BlockManagerId(0, 172.17.0.3, 42589))] in 2 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:08:09 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@2a069e29,BlockManagerId(0, 172.17.0.3, 42589))] in 3 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:08:09 WARN executor.Executor: Issue communicating with driver in heartbeater
> org.apache.spark.SparkException: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@2a069e29,BlockManagerId(0, 172.17.0.3, 42589))]
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:119)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	... 13 more
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:08:13 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@73f332ca,BlockManagerId(0, 172.17.0.3, 42589))] in 1 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:08:16 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@73f332ca,BlockManagerId(0, 172.17.0.3, 42589))] in 2 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:08:19 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@73f332ca,BlockManagerId(0, 172.17.0.3, 42589))] in 3 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:08:19 WARN executor.Executor: Issue communicating with driver in heartbeater
> org.apache.spark.SparkException: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@73f332ca,BlockManagerId(0, 172.17.0.3, 42589))]
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:119)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	... 13 more
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:08:23 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@59306b2b,BlockManagerId(0, 172.17.0.3, 42589))] in 1 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:08:26 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@59306b2b,BlockManagerId(0, 172.17.0.3, 42589))] in 2 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:08:29 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@59306b2b,BlockManagerId(0, 172.17.0.3, 42589))] in 3 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:08:29 WARN executor.Executor: Issue communicating with driver in heartbeater
> org.apache.spark.SparkException: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@59306b2b,BlockManagerId(0, 172.17.0.3, 42589))]
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:119)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	... 13 more
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:08:33 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@12a7473f,BlockManagerId(0, 172.17.0.3, 42589))] in 1 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:08:36 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@12a7473f,BlockManagerId(0, 172.17.0.3, 42589))] in 2 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:08:39 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@12a7473f,BlockManagerId(0, 172.17.0.3, 42589))] in 3 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:08:39 WARN executor.Executor: Issue communicating with driver in heartbeater
> org.apache.spark.SparkException: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@12a7473f,BlockManagerId(0, 172.17.0.3, 42589))]
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:119)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	... 13 more
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:08:43 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@7fdcb282,BlockManagerId(0, 172.17.0.3, 42589))] in 1 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:08:46 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@7fdcb282,BlockManagerId(0, 172.17.0.3, 42589))] in 2 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:08:49 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@7fdcb282,BlockManagerId(0, 172.17.0.3, 42589))] in 3 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:08:49 WARN executor.Executor: Issue communicating with driver in heartbeater
> org.apache.spark.SparkException: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@7fdcb282,BlockManagerId(0, 172.17.0.3, 42589))]
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:119)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	... 13 more
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:08:53 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@6973a36c,BlockManagerId(0, 172.17.0.3, 42589))] in 1 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:08:56 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@6973a36c,BlockManagerId(0, 172.17.0.3, 42589))] in 2 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:08:59 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@6973a36c,BlockManagerId(0, 172.17.0.3, 42589))] in 3 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:08:59 WARN executor.Executor: Issue communicating with driver in heartbeater
> org.apache.spark.SparkException: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@6973a36c,BlockManagerId(0, 172.17.0.3, 42589))]
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:119)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	... 13 more
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:09:03 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@558b31b0,BlockManagerId(0, 172.17.0.3, 42589))] in 1 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:09:06 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@558b31b0,BlockManagerId(0, 172.17.0.3, 42589))] in 2 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:09:09 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@558b31b0,BlockManagerId(0, 172.17.0.3, 42589))] in 3 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:09:09 WARN executor.Executor: Issue communicating with driver in heartbeater
> org.apache.spark.SparkException: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@558b31b0,BlockManagerId(0, 172.17.0.3, 42589))]
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:119)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	... 13 more
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:09:13 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@4d9e6506,BlockManagerId(0, 172.17.0.3, 42589))] in 1 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:09:16 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@4d9e6506,BlockManagerId(0, 172.17.0.3, 42589))] in 2 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:09:19 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@4d9e6506,BlockManagerId(0, 172.17.0.3, 42589))] in 3 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:09:19 WARN executor.Executor: Issue communicating with driver in heartbeater
> org.apache.spark.SparkException: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@4d9e6506,BlockManagerId(0, 172.17.0.3, 42589))]
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:119)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	... 13 more
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:09:23 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@4269511d,BlockManagerId(0, 172.17.0.3, 42589))] in 1 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:09:26 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@4269511d,BlockManagerId(0, 172.17.0.3, 42589))] in 2 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:09:29 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@4269511d,BlockManagerId(0, 172.17.0.3, 42589))] in 3 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:09:29 WARN executor.Executor: Issue communicating with driver in heartbeater
> org.apache.spark.SparkException: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@4269511d,BlockManagerId(0, 172.17.0.3, 42589))]
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:119)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	... 13 more
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:09:33 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@7a2f6c16,BlockManagerId(0, 172.17.0.3, 42589))] in 1 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:09:36 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@7a2f6c16,BlockManagerId(0, 172.17.0.3, 42589))] in 2 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:09:39 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@7a2f6c16,BlockManagerId(0, 172.17.0.3, 42589))] in 3 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:09:39 WARN executor.Executor: Issue communicating with driver in heartbeater
> org.apache.spark.SparkException: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@7a2f6c16,BlockManagerId(0, 172.17.0.3, 42589))]
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:119)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	... 13 more
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:09:43 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@72258aa6,BlockManagerId(0, 172.17.0.3, 42589))] in 1 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:09:46 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@72258aa6,BlockManagerId(0, 172.17.0.3, 42589))] in 2 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:09:49 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@72258aa6,BlockManagerId(0, 172.17.0.3, 42589))] in 3 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:09:49 WARN executor.Executor: Issue communicating with driver in heartbeater
> org.apache.spark.SparkException: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@72258aa6,BlockManagerId(0, 172.17.0.3, 42589))]
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:119)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	... 13 more
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:09:53 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@3bb94d9,BlockManagerId(0, 172.17.0.3, 42589))] in 1 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:09:56 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@3bb94d9,BlockManagerId(0, 172.17.0.3, 42589))] in 2 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:09:59 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@3bb94d9,BlockManagerId(0, 172.17.0.3, 42589))] in 3 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:09:59 WARN executor.Executor: Issue communicating with driver in heartbeater
> org.apache.spark.SparkException: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@3bb94d9,BlockManagerId(0, 172.17.0.3, 42589))]
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:119)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	... 13 more
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:10:03 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@36504236,BlockManagerId(0, 172.17.0.3, 42589))] in 1 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:10:06 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@36504236,BlockManagerId(0, 172.17.0.3, 42589))] in 2 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:10:09 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@36504236,BlockManagerId(0, 172.17.0.3, 42589))] in 3 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:10:09 WARN executor.Executor: Issue communicating with driver in heartbeater
> org.apache.spark.SparkException: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@36504236,BlockManagerId(0, 172.17.0.3, 42589))]
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:119)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	... 13 more
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:10:13 WARN netty.NettyRpcEndpointRef: Error sending message [message = Heartbeat(0,[Lscala.Tuple2;@73c9e8a1,BlockManagerId(0, 172.17.0.3, 42589))] in 1 attempts
> org.apache.spark.SparkException: Exception thrown in awaitResult
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:77)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$1.applyOrElse(RpcTimeout.scala:75)
> 	at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at org.apache.spark.rpc.RpcTimeout$$anonfun$addMessageIfTimeout$1.applyOrElse(RpcTimeout.scala:59)
> 	at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167)
> 	at org.apache.spark.rpc.RpcTimeout.awaitResult(RpcTimeout.scala:83)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
> 	at org.apache.spark.executor.Executor.org$apache$spark$executor$Executor$$reportHeartBeat(Executor.scala:518)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply$mcV$sp(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.executor.Executor$$anon$1$$anonfun$run$1.apply(Executor.scala:547)
> 	at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1877)
> 	at org.apache.spark.executor.Executor$$anon$1.run(Executor.scala:547)
> 	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> 	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> 	at java.lang.Thread.run(Thread.java:745)
> Caused by: java.util.ConcurrentModificationException
> 	at java.util.ArrayList.writeObject(ArrayList.java:766)
> 	at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
> 	at java.util.Collections$SynchronizedCollection.writeObject(Collections.java:2081)
> 	at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:498)
> 	at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1028)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
> 	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
> 	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
> 	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
> 	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
> 	at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:43)
> 	at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:100)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.serialize(NettyRpcEnv.scala:253)
> 	at org.apache.spark.rpc.netty.NettyRpcEnv.ask(NettyRpcEnv.scala:227)
> 	at org.apache.spark.rpc.netty.NettyRpcEndpointRef.ask(NettyRpcEnv.scala:508)
> 	at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:101)
> 	... 13 more
> 16/11/17 21:10:14 INFO executor.CoarseGrainedExecutorBackend: Got assigned task 1
> 16/11/17 21:10:14 INFO executor.Executor: Running task 0.1 in stage 0.0 (TID 1)
> 16/11/17 21:10:14 ERROR executor.CoarseGrainedExecutorBackend: RECEIVED SIGNAL T



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscribe@spark.apache.org
For additional commands, e-mail: issues-help@spark.apache.org