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https://issues.apache.org/jira/browse/HADOOP-15538?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16514846#comment-16514846
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Yongjun Zhang commented on HADOOP-15538:
----------------------------------------
There is also the other thread reported in HADOOP-15530 blocked at:
[https://insight.io/github.com/AdoptOpenJDK/openjdk-jdk8u/blob/dev/jdk/src/share/classes/java/util/concurrent/FutureTask.java?line=396]
There is a chance that this thread is in play but I have not figured out how.
I wish the comment here
[https://insight.io/github.com/JetBrains/jdk8u_hotspot/blob/master/src/share/vm/services/threadService.cpp?line=906]
could give some explanation what are the possible scenarios that the lock owner
is not findable.
This is likely a jdk bug: a lock has an associated owner thread address, but
the thread can not be found. It seems to me that the only hope now is to get
heapdump and coredump to find clue.
Any comment/insight is very much appreciated.
> 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
> 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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