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https://issues.apache.org/jira/browse/MAPREDUCE-4164?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13256089#comment-13256089
 ] 

Mayank Bansal commented on MAPREDUCE-4164:
------------------------------------------

1. TaskReporter thread sends status updates/pings periodically to TaskTracker. 
If it needs to send the task progress, it sends STATUS_UPDATE message
to TaskTracker. Otherwise, it sends a PING signal to check if the TaskTracker 
is alive.

2. When the map/reduce phase is over, it calls stopCommunicationThread() which 
interrupts ping/statusupdate thread.

3. If the system was trying to communicate with the server at the time of 
interrupts, it breaks the connection to the
server.Since the interrupt was issued, the stream throws 
ClosedByInterruptException.

5. However in Client.java, Client keeps waiting for the response and it 
basically times out and re-throws this exception.

                
> Hadoop 22 Exception thrown after task completion causes its reexecution
> -----------------------------------------------------------------------
>
>                 Key: MAPREDUCE-4164
>                 URL: https://issues.apache.org/jira/browse/MAPREDUCE-4164
>             Project: Hadoop Map/Reduce
>          Issue Type: Bug
>          Components: tasktracker
>            Reporter: Mayank Bansal
>            Assignee: Mayank Bansal
>         Attachments: MAPREDUCE-4164.patch
>
>
> 2012-02-28 19:17:08,504 INFO org.apache.hadoop.mapred.Merger: Down to the 
> last merge-pass, with 3 segments left of total size: 1969310 bytes
> 2012-02-28 19:17:08,694 INFO org.apache.hadoop.mapred.Task: 
> Task:attempt_201202272306_0794_m_000094_0 is done. And is in the process of 
> commiting
> 2012-02-28 19:18:08,774 INFO org.apache.hadoop.mapred.Task: Communication 
> exception: java.io.IOException: Call to /127.0.0.1:35400 failed on local 
> exception: java.nio.channels.ClosedByInterruptException
> at org.apache.hadoop.ipc.Client.wrapException(Client.java:1094)
> at org.apache.hadoop.ipc.Client.call(Client.java:1062)
> at 
> org.apache.hadoop.ipc.WritableRpcEngine$Invoker.invoke(WritableRpcEngine.java:198)
> at $Proxy0.statusUpdate(Unknown Source)
> at org.apache.hadoop.mapred.Task$TaskReporter.run(Task.java:650)
> at java.lang.Thread.run(Thread.java:662)
> Caused by: java.nio.channels.ClosedByInterruptException
> at 
> java.nio.channels.spi.AbstractInterruptibleChannel.end(AbstractInterruptibleChannel.java:184)
> at sun.nio.ch.SocketChannelImpl.write(SocketChannelImpl.java:341)
> at 
> org.apache.hadoop.net.SocketOutputStream$Writer.performIO(SocketOutputStream.java:60)
> at 
> org.apache.hadoop.net.SocketIOWithTimeout.doIO(SocketIOWithTimeout.java:142)
> at org.apache.hadoop.net.SocketOutputStream.write(SocketOutputStream.java:151)
> at org.apache.hadoop.net.SocketOutputStream.write(SocketOutputStream.java:112)
> at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:65)
> at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:123)
> at java.io.DataOutputStream.flush(DataOutputStream.java:106)
> at org.apache.hadoop.ipc.Client$Connection.sendParam(Client.java:769)
> at org.apache.hadoop.ipc.Client.call(Client.java:1040)
> ... 4 more
> 2012-02-28 19:18:08,825 INFO org.apache.hadoop.mapred.Task: Task 
> 'attempt_201202272306_0794_m_000094_0' done.
> ================>>>>>> SHOULD be <++++++++++++++
> 2012-02-28 19:17:02,214 INFO org.apache.hadoop.mapred.Merger: Down to the 
> last merge-pass, with 3 segments left of total size: 1974104 bytes
> 2012-02-28 19:17:02,408 INFO org.apache.hadoop.mapred.Task: 
> Task:attempt_201202272306_0794_m_000000_0 is done. And is in the process of 
> commiting
> 2012-02-28 19:17:02,519 INFO org.apache.hadoop.mapred.Task: Task 
> 'attempt_201202272306_0794_m_000000_0' done. 

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