hadoop-common-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Doug Cutting (JIRA)" <j...@apache.org>
Subject [jira] Resolved: (HADOOP-16) RPC call times out while indexing map task is computing splits
Date Thu, 02 Mar 2006 23:10:39 GMT
     [ http://issues.apache.org/jira/browse/HADOOP-16?page=all ]
     
Doug Cutting resolved HADOOP-16:
--------------------------------

    Resolution: Fixed

I applied Mike's patch, with a few small changes, fixing an NPE and ArrayOutOfBounds in dfs.

There's still a bug where, with mapred.tasktracker.tasks.maximum=2, only a single map and
a single reduce are running on each node.  I believe the intent is that there should be up
to two of each related to a single job, so that the reduce tasks can be copying data while
the maps are still running.

> RPC call times out while indexing map task is computing splits
> --------------------------------------------------------------
>
>          Key: HADOOP-16
>          URL: http://issues.apache.org/jira/browse/HADOOP-16
>      Project: Hadoop
>         Type: Bug
>   Components: mapred
>     Versions: 0.1
>  Environment: MapReduce multi-computer crawl environment: 11 machines (1 master with
JobTracker/NameNode, 10 slaves with TaskTrackers/DataNodes)
>     Reporter: Chris Schneider
>     Assignee: Mike Cafarella
>      Fix For: 0.1
>  Attachments: patch.16, patch_h16.v0
>
> We've been using Nutch 0.8 (MapReduce) to perform some internet crawling. Things seemed
to be going well until...
> 060129 222409 Lost tracker 'tracker_56288'
> 060129 222409 Task 'task_m_10gs5f' has been lost.
> 060129 222409 Task 'task_m_10qhzr' has been lost.
>    ........
>    ........
> 060129 222409 Task 'task_r_zggbwu' has been lost.
> 060129 222409 Task 'task_r_zh8dao' has been lost.
> 060129 222455 Server handler 8 on 8010 caught: java.net.SocketException: Socket closed
> java.net.SocketException: Socket closed
>         at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:99)
>         at java.net.SocketOutputStream.write(SocketOutputStream.java:136)
>         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.nutch.ipc.Server$Handler.run(Server.java:216)
> 060129 222455 Adding task 'task_m_cia5po' to set for tracker 'tracker_56288'
> 060129 223711 Adding task 'task_m_ffv59i' to set for tracker 'tracker_25647'
> I'm hoping that someone could explain why task_m_cia5po got added to tracker_56288 after
this tracker was lost.
> The Crawl .main process died with the following output:
> 060129 221129 Indexer: adding segment: /user/crawler/crawl-20060129091444/segments/20060129200246
> Exception in thread "main" java.io.IOException: timed out waiting for response
>     at org.apache.nutch.ipc.Client.call(Client.java:296)
>     at org.apache.nutch.ipc.RPC$Invoker.invoke(RPC.java:127)
>     at $Proxy1.submitJob(Unknown Source)
>     at org.apache.nutch.mapred.JobClient.submitJob(JobClient.java:259)
>     at org.apache.nutch.mapred.JobClient.runJob(JobClient.java:288)
>     at org.apache.nutch.indexer.Indexer.index(Indexer.java:263)
>     at org.apache.nutch.crawl.Crawl.main(Crawl.java:127)
> However, it definitely seems as if the JobTracker is still waiting for the job to finish
(no failed jobs).
> Doug Cutting's response:
> The bug here is that the RPC call times out while the map task is computing splits. 
The fix is that the job tracker should not compute splits until after it has returned from
the submitJob RPC.  Please submit a bug in Jira to help remind us to fix this.

-- 
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators:
   http://issues.apache.org/jira/secure/Administrators.jspa
-
For more information on JIRA, see:
   http://www.atlassian.com/software/jira


Mime
View raw message