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Posted to common-issues@hadoop.apache.org by "Yongjun Zhang (JIRA)" <ji...@apache.org> on 2018/07/11 16:21:00 UTC

[jira] [Comment Edited] (HADOOP-15538) Possible RPC deadlock in Client

    [ https://issues.apache.org/jira/browse/HADOOP-15538?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16540325#comment-16540325 ] 

Yongjun Zhang edited comment on HADOOP-15538 at 7/11/18 4:20 PM:
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BTW, I agree very much with 
{quote}
The bottom line is that I think we should really sniff for the native code in the app that runs this HDFS Client, and then check if that native code is doing something unusual.
{quote}


was (Author: yzhangal):
BTW, I agree very much with 
{code:java}

The bottom line is that I think we should really sniff for the native code in the app that runs this HDFS Client, and then check if that native code is doing something unusual.{code}

> Possible RPC deadlock in Client
> -------------------------------
>
>                 Key: HADOOP-15538
>                 URL: https://issues.apache.org/jira/browse/HADOOP-15538
>             Project: Hadoop Common
>          Issue Type: Bug
>          Components: common
>            Reporter: Yongjun Zhang
>            Assignee: Yongjun Zhang
>            Priority: Major
>         Attachments: t1+13min.jstack, t1.jstack
>
>
> We have a jstack collection that spans 13 minutes. One frame per ~1.5 minutes. And for each of the frame, I observed the following:
> {code:java}
> Found one Java-level deadlock:
> =============================
> "IPC Parameter Sending Thread #294":
>   waiting to lock monitor 0x00007f68f21f3188 (object 0x0000000621745390, a java.lang.Object),
>   which is held by UNKNOWN_owner_addr=0x00007f68332e2800
> Java stack information for the threads listed above:
> ===================================================
> "IPC Parameter Sending Thread #294":
>         at sun.nio.ch.SocketChannelImpl.ensureWriteOpen(SocketChannelImpl.java:268)
>         - waiting to lock <0x0000000621745390> (a java.lang.Object)
>         at sun.nio.ch.SocketChannelImpl.write(SocketChannelImpl.java:461)
>         - locked <0x0000000621745380> (a java.lang.Object)
>         at org.apache.hadoop.net.SocketOutputStream$Writer.performIO(SocketOutputStream.java:63)
>         at org.apache.hadoop.net.SocketIOWithTimeout.doIO(SocketIOWithTimeout.java:142)
>         at org.apache.hadoop.net.SocketOutputStream.write(SocketOutputStream.java:159)
>         at org.apache.hadoop.net.SocketOutputStream.write(SocketOutputStream.java:117)
>         at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82)
>         at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:140)
>         - locked <0x0000000621749850> (a java.io.BufferedOutputStream)
>         at java.io.DataOutputStream.flush(DataOutputStream.java:123)
>         at org.apache.hadoop.ipc.Client$Connection$3.run(Client.java:1072)
>         - locked <0x000000062174b878> (a java.io.DataOutputStream)
>         at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
>         at java.util.concurrent.FutureTask.run(FutureTask.java:266)
>         at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
>         at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
>         at java.lang.Thread.run(Thread.java:748)
> Found one Java-level deadlock:
> =============================
> "IPC Client (297602875) connection to x.y.z.p:8020 from impala":
>   waiting to lock monitor 0x00007f68f21f3188 (object 0x0000000621745390, a java.lang.Object),
>   which is held by UNKNOWN_owner_addr=0x00007f68332e2800
> Java stack information for the threads listed above:
> ===================================================
> "IPC Client (297602875) connection to x.y.z.p:8020 from impala":
>         at sun.nio.ch.SocketChannelImpl.readerCleanup(SocketChannelImpl.java:279)
>         - waiting to lock <0x0000000621745390> (a java.lang.Object)
>         at sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:390)
>         - locked <0x0000000621745370> (a java.lang.Object)
>         at org.apache.hadoop.net.SocketInputStream$Reader.performIO(SocketInputStream.java:57)
>         at org.apache.hadoop.net.SocketIOWithTimeout.doIO(SocketIOWithTimeout.java:142)
>         at org.apache.hadoop.net.SocketInputStream.read(SocketInputStream.java:161)
>         at org.apache.hadoop.net.SocketInputStream.read(SocketInputStream.java:131)
>         at java.io.FilterInputStream.read(FilterInputStream.java:133)
>         at java.io.FilterInputStream.read(FilterInputStream.java:133)
>         at org.apache.hadoop.ipc.Client$Connection$PingInputStream.read(Client.java:553)
>         at java.io.BufferedInputStream.fill(BufferedInputStream.java:246)
>         at java.io.BufferedInputStream.read(BufferedInputStream.java:265)
>         - locked <0x00000006217476f0> (a java.io.BufferedInputStream)
>         at java.io.DataInputStream.readInt(DataInputStream.java:387)
>         at org.apache.hadoop.ipc.Client$Connection.receiveRpcResponse(Client.java:1113)
>         at org.apache.hadoop.ipc.Client$Connection.run(Client.java:1006)
> Found 2 deadlocks.
> {code}
> This happens with jdk1.8.0_162 on 2.6.32-696.18.7.el6.x86_64.
> The code appears to match [https://insight.io/github.com/AdoptOpenJDK/openjdk-jdk8u/tree/dev/jdk/src/share/classes/sun/nio/ch/SocketChannelImpl.java].
> The first thread is blocked at:
> [https://insight.io/github.com/AdoptOpenJDK/openjdk-jdk8u/blob/dev/jdk/src/share/classes/sun/nio/ch/SocketChannelImpl.java?line=268]
> The second thread is blocked at:
>  [https://insight.io/github.com/AdoptOpenJDK/openjdk-jdk8u/blob/dev/jdk/src/share/classes/sun/nio/ch/SocketChannelImpl.java?line=279]
> There are two issues here:
>  # There seems to be a real deadlock because the stacks remain the same even if the first an last jstack frames captured is 13 minutes apart.
>  # Java deadlock report seems to be problematic, two threads that have deadlock should not be blocked on the same lock, but they appear to be in this case: the same SocketChannelImpl's stateLock.
> I found a relevant jdk jira [https://bugs.openjdk.java.net/browse/JDK-8007476], it explains where two deadlocks are reported and they are really for the same deadlock.
> I don't see a similar report about this issue in jdk jira database, and I'm thinking about filing a jdk jira for that, but would like to throw some discussion here before that.
> Issue#1 is important, because the client is hanging, which indicate a real problem; however, without a correct report before issue#2 is fixed, it's not clear how the deadlock really looks like.
> Thanks.



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