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Posted to common-issues@hadoop.apache.org by "Yongjun Zhang (JIRA)" <ji...@apache.org> on 2018/06/14 07:40:00 UTC
[jira] [Comment Edited] (HADOOP-15538) Possible deadlock in Client
[ https://issues.apache.org/jira/browse/HADOOP-15538?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16512076#comment-16512076 ]
Yongjun Zhang edited comment on HADOOP-15538 at 6/14/18 7:39 AM:
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Hm, I noticed that in [https://bugs.openjdk.java.net/browse/JDK-8007476], The "which is held by UNKNOWN_owner_addr" shows two different values for the two threads involved in the deadlock, one corresponds to each of these two threads.
{code:java}
Found one Java-level deadlock:
=============================
"Worker-1":
waiting to lock monitor 0x02f60e54 (object 0x1026ce00, a java.lang.Object),
which is held by UNKNOWN_owner_addr=0x0352fc54
......
Found one Java-level deadlock:
=============================
"Worker-0":
waiting to lock monitor 0x02f601bc (object 0x1026ce08, a java.lang.Object),
which is held by UNKNOWN_owner_addr=0x0357fbd4
{code}
However, in the case I reported here, they point to the same value:
{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
......
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
{code}
and this value could just be a third thread, thus two deadlock pairs <thread1, thread3>, <thread2, thread3>. This explains issue#2. However, I wish java stack dump could be more clear about why UNKNOWN_owner_addr here, what thread this really is.
was (Author: yzhangal):
Hm, I noticed that in https://bugs.openjdk.java.net/browse/JDK-8007476, The "which is held by UNKNOWN_owner_addr" shows two different values for the two threads involved in the deadlock, one corresponds to each of these two threads.
{code}
Found one Java-level deadlock:
=============================
"Worker-1":
waiting to lock monitor 0x02f60e54 (object 0x1026ce00, a java.lang.Object),
which is held by UNKNOWN_owner_addr=0x0352fc54
......
Found one Java-level deadlock:
=============================
"Worker-0":
waiting to lock monitor 0x02f601bc (object 0x1026ce08, a java.lang.Object),
which is held by UNKNOWN_owner_addr=0x0357fbd4
{code}
However, in the case I reported here, they point to the same value:
{code}
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
......
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
{code}
and this value could just be a third thread, thus two deadlock pairs <thread1, thread3>, <thread2, thread3>. I wish java stack dump could be more clear about why UNKNOWN_owner_addr here, what thread this really is.
> Possible 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
>
> We have a jstack collection that spans 13 minutes. Once frame per ~1.5 minutes. And for each of the frame, I observed the following:
> {code}
> 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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