Yongjun Zhang created HADOOP-15538:
--------------------------------------
Summary: Possible dead lock 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
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, and 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:
1. 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.
2. 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 but they are really for the same
deadlock.
I don't see a similar report about this 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.
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