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Posted to issues@spark.apache.org by "Max Xie (JIRA)" <ji...@apache.org> on 2019/03/25 09:59:00 UTC

[jira] [Created] (SPARK-27267) spark 2.4 use 1.1.7.x snappy-java, but its behavior is different from 1.1.2.x

Max  Xie created SPARK-27267:
--------------------------------

             Summary: spark 2.4 use  1.1.7.x  snappy-java, but its behavior is different from 1.1.2.x 
                 Key: SPARK-27267
                 URL: https://issues.apache.org/jira/browse/SPARK-27267
             Project: Spark
          Issue Type: Bug
          Components: Block Manager, Spark Core
    Affects Versions: 2.4.0
         Environment: spark.rdd.compress=true

spark.io.compression.codec =snappy

spark 2.4 in hadoop 2.6 with hive
            Reporter: Max  Xie


I use pyspark  like that

```

from pyspark.storagelevel import StorageLevel
df=spark.sql("select * from xzn.person")
df.persist(StorageLevel(False, True, False, False))
df.count()

```

table person is a simple table stored as orc files and some orc files is empty. When I run the query, it throw the error : 

```

19/03/22 21:46:31 INFO MemoryStore:54 - Block rdd_2_1 stored as values in memory (estimated size 0.0 B, free 1662.6 MB)
19/03/22 21:46:31 INFO FileScanRDD:54 - Reading File path: viewfs://name/xzn.db/person/part-00011, range: 0-49, partition values: [empty row]
19/03/22 21:46:31 INFO FileScanRDD:54 - Reading File path: viewfs://name/xzn.db/person/part-00011_copy_1, range: 0-49, partition values: [empty row]
19/03/22 21:46:31 INFO FileScanRDD:54 - Reading File path: viewfs://name/xzn.db/person/part-00012, range: 0-49, partition values: [empty row]
19/03/22 21:46:31 INFO FileScanRDD:54 - Reading File path: viewfs://name/xzn.db/person/part-00012_copy_1, range: 0-49, partition values: [empty row]
19/03/22 21:46:31 INFO FileScanRDD:54 - Reading File path: viewfs://name/xzn.db/person/part-00013, range: 0-49, partition values: [empty row]
19/03/22 21:46:31 ERROR Executor:91 - Exception in task 1.0 in stage 0.0 (TID 1)
org.xerial.snappy.SnappyIOException: [EMPTY_INPUT] Cannot decompress empty stream
 at org.xerial.snappy.SnappyInputStream.readHeader(SnappyInputStream.java:94)
 at org.xerial.snappy.SnappyInputStream.<init>(SnappyInputStream.java:59)
 at org.apache.spark.io.SnappyCompressionCodec.compressedInputStream(CompressionCodec.scala:164)
 at org.apache.spark.serializer.SerializerManager.wrapForCompression(SerializerManager.scala:163)
 at org.apache.spark.serializer.SerializerManager.dataDeserializeStream(SerializerManager.scala:209)
 at org.apache.spark.storage.BlockManager.getLocalValues(BlockManager.scala:596)
 at org.apache.spark.storage.BlockManager.getOrElseUpdate(BlockManager.scala:886)
 at org.apache.spark.rdd.RDD.getOrCompute(RDD.scala:335)
 at org.apache.spark.rdd.RDD.iterator(RDD.scala:286)
 at org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:52)
 at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:324)
 at org.apache.spark.rdd.RDD.iterator(RDD.scala:288)
 at org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:52)
 at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:324)
 at org.apache.spark.rdd.RDD.iterator(RDD.scala:288)
 at org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:52)
 at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:324)
 at org.apache.spark.rdd.RDD.iterator(RDD.scala:288)
 at org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:52)
 at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:324)
 at org.apache.spark.rdd.RDD.iterator(RDD.scala:288)
 at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:99)
 at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:55)
 at org.apache.spark.scheduler.Task.run(Task.scala:121)
 at org.apache.spark.executor.Executor$TaskRunner$$anonfun$10.apply(Executor.scala:402)
 at org.apache.spark.util.Utils$.tryWithSafeFinally(Utils.scala:1360)
 at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:408)
 at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
 at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
 at java.lang.Thread.run(Thread.java:748)
```

After I search it, I find that 1.1.7.x  snappy-java 's behavior is different from 1.1.2.x (that  spark 2.0.2 use this version). SnappyOutputStream in 1.1.2.x version always writes a snappy header whether or not to write a value,  but  SnappyOutputStream in 1.1.7.x don't generate header if u don't write value into it, so in spark 2.4 if RDD cache a empty value, memoryStore will not cache any bytes ( no snappy header ),  then it will throw the empty error. 

 

Maybe we can change SnappyOutputStream to fix it in 1.1.7.x snappy-java, there is my SnappyOutputStream method compressInput code 

```

protected void compressInput()
 throws IOException
 {
 // generate header 
 if (!headerWritten) {
 outputCursor = writeHeader();
 headerWritten = true;
 }

 if (inputCursor <= 0) {
 return; // no need to dump
 }

// if (!headerWritten) {
// outputCursor = writeHeader();
// headerWritten = true;
// }

 // Compress and dump the buffer content
 if (!hasSufficientOutputBufferFor(inputCursor)) {
 dumpOutput();
 }

 writeBlockPreemble();

 int compressedSize = Snappy.compress(inputBuffer, 0, inputCursor, outputBuffer, outputCursor + 4);
 // Write compressed data size
 writeInt(outputBuffer, outputCursor, compressedSize);
 outputCursor += 4 + compressedSize;
 inputCursor = 0;
 }

```

 

 

 

 



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