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https://issues.apache.org/jira/browse/HADOOP-5380?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12977535#action_12977535
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Kan Zhang commented on HADOOP-5380:
-----------------------------------
A couple questions.
> Since the interrupt was issued, the stream throws ClosedByInterruptException
> and doesn't send any information.
Which stream is this and where was the ClosedByInterruptException thrown? From
your log, the exception that IPC client sees is ClosedChannelException. If so,
which thread causes this connection to be closed? Just trying to understand the
sequence of events that happened. Please attach relevant log if possible.
> Calls from running tasks to TaskTracker methods sometimes fail and incur a
> 60s timeout
> --------------------------------------------------------------------------------------
>
> Key: HADOOP-5380
> URL: https://issues.apache.org/jira/browse/HADOOP-5380
> Project: Hadoop Common
> Issue Type: Bug
> Affects Versions: 0.20.1
> Reporter: Matei Zaharia
> Attachments: HADOOP-5380.Y.20.branch.patch
>
>
> I'm seeing some map tasks in my jobs take 1 minute to commit after they
> finish the map computation. On the map side, the output looks like this:
> <code>
> 2009-03-02 21:30:54,384 INFO org.apache.hadoop.metrics.jvm.JvmMetrics: Cannot
> initialize JVM Metrics with processName=MAP, sessionId= - already initialized
> 2009-03-02 21:30:54,437 INFO org.apache.hadoop.mapred.MapTask:
> numReduceTasks: 800
> 2009-03-02 21:30:54,437 INFO org.apache.hadoop.mapred.MapTask: io.sort.mb =
> 300
> 2009-03-02 21:30:55,493 INFO org.apache.hadoop.mapred.MapTask: data buffer =
> 239075328/298844160
> 2009-03-02 21:30:55,494 INFO org.apache.hadoop.mapred.MapTask: record buffer
> = 786432/983040
> 2009-03-02 21:31:00,381 INFO org.apache.hadoop.mapred.MapTask: Starting flush
> of map output
> 2009-03-02 21:31:07,892 INFO org.apache.hadoop.mapred.MapTask: Finished spill > 0
> 2009-03-02 21:31:07,951 INFO org.apache.hadoop.mapred.TaskRunner:
> Task:attempt_200903022127_0001_m_003163_0 is done. And is in the process of
> commiting
> 2009-03-02 21:32:07,949 INFO org.apache.hadoop.mapred.TaskRunner:
> Communication exception: java.io.IOException: Call to /127.0.0.1:50311 failed
> on local exception: java.nio.channels.ClosedChannelException
> at org.apache.hadoop.ipc.Client.wrapException(Client.java:765)
> at org.apache.hadoop.ipc.Client.call(Client.java:733)
> at org.apache.hadoop.ipc.RPC$Invoker.invoke(RPC.java:220)
> at org.apache.hadoop.mapred.$Proxy0.ping(Unknown Source)
> at org.apache.hadoop.mapred.Task$TaskReporter.run(Task.java:525)
> at java.lang.Thread.run(Thread.java:619)
> Caused by: java.nio.channels.ClosedChannelException
> at
> java.nio.channels.spi.AbstractSelectableChannel.register(AbstractSelectableChannel.java:167)
> at
> java.nio.channels.SelectableChannel.register(SelectableChannel.java:254)
> at
> org.apache.hadoop.net.SocketIOWithTimeout$SelectorPool.select(SocketIOWithTimeout.java:331)
> at
> org.apache.hadoop.net.SocketIOWithTimeout.doIO(SocketIOWithTimeout.java:157)
> at
> org.apache.hadoop.net.SocketInputStream.read(SocketInputStream.java:155)
> at
> org.apache.hadoop.net.SocketInputStream.read(SocketInputStream.java:128)
> at java.io.FilterInputStream.read(FilterInputStream.java:116)
> at
> org.apache.hadoop.ipc.Client$Connection$PingInputStream.read(Client.java:276)
> at java.io.BufferedInputStream.fill(BufferedInputStream.java:218)
> at java.io.BufferedInputStream.read(BufferedInputStream.java:237)
> at java.io.DataInputStream.readInt(DataInputStream.java:370)
> at
> org.apache.hadoop.ipc.Client$Connection.receiveResponse(Client.java:501)
> at org.apache.hadoop.ipc.Client$Connection.run(Client.java:446)
> 2009-03-02 21:32:07,953 INFO org.apache.hadoop.mapred.TaskRunner: Task
> 'attempt_200903022127_0001_m_003163_0' done.
> </code>
> In the TaskTracker log, it looks like this:
> <code>
> 2009-03-02 21:31:08,110 WARN org.apache.hadoop.ipc.Server: IPC Server
> Responder, call ping(attempt_200903022127_0001_m_003163_0) from
> 127.0.0.1:56884: output error
> 2009-03-02 21:31:08,111 INFO org.apache.hadoop.ipc.Server: IPC Server handler
> 10 on 50311 caught: java.nio.channels.ClosedChannelException
> at
> sun.nio.ch.SocketChannelImpl.ensureWriteOpen(SocketChannelImpl.java:126)
> at sun.nio.ch.SocketChannelImpl.write(SocketChannelImpl.java:324) at
> org.apache.hadoop.ipc.Server.channelWrite(Server.java:1195)
> at org.apache.hadoop.ipc.Server.access$1900(Server.java:77)
> at org.apache.hadoop.ipc.Server$Responder.processResponse(Server.java:613)
> at org.apache.hadoop.ipc.Server$Responder.doRespond(Server.java:677)
> at org.apache.hadoop.ipc.Server$Handler.run(Server.java:981)
> </code>
> Note that the task actually seemed to commit - it didn't get speculatively
> executed or anything. However, the job wasn't able to continue until this one
> task was done. Both parties seem to think the channel was closed. How does
> the channel get closed externally? If closing it from outside is unavoidable,
> maybe the right thing to do is to set a much lower timeout, because 1 minute
> delay can be pretty significant for a small job.
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