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https://issues.apache.org/jira/browse/MAPREDUCE-4772?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13493972#comment-13493972
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Hudson commented on MAPREDUCE-4772:
-----------------------------------
Integrated in Hadoop-Hdfs-0.23-Build #430 (See
[https://builds.apache.org/job/Hadoop-Hdfs-0.23-Build/430/])
svn merge -c 1407118 FIXES: MAPREDUCE-4772. Fetch failures can take way too
long for a map to be restarted (bobby) (Revision 1407128)
Result = SUCCESS
bobby : http://svn.apache.org/viewcvs.cgi/?root=Apache-SVN&view=rev&rev=1407128
Files :
* /hadoop/common/branches/branch-0.23/hadoop-mapreduce-project/CHANGES.txt
*
/hadoop/common/branches/branch-0.23/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/main/java/org/apache/hadoop/mapreduce/v2/app/job/impl/JobImpl.java
*
/hadoop/common/branches/branch-0.23/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/test/java/org/apache/hadoop/mapreduce/v2/app/TestFetchFailure.java
*
/hadoop/common/branches/branch-0.23/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/MRJobConfig.java
*
/hadoop/common/branches/branch-0.23/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/task/reduce/Fetcher.java
*
/hadoop/common/branches/branch-0.23/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/task/reduce/ShuffleScheduler.java
*
/hadoop/common/branches/branch-0.23/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/resources/mapred-default.xml
*
/hadoop/common/branches/branch-0.23/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/test/java/org/apache/hadoop/mapreduce/task/reduce/TestFetcher.java
> Fetch failures can take way too long for a map to be restarted
> --------------------------------------------------------------
>
> Key: MAPREDUCE-4772
> URL: https://issues.apache.org/jira/browse/MAPREDUCE-4772
> Project: Hadoop Map/Reduce
> Issue Type: Bug
> Components: mrv2
> Affects Versions: 0.23.4
> Reporter: Robert Joseph Evans
> Assignee: Robert Joseph Evans
> Priority: Critical
> Fix For: 3.0.0, 2.0.3-alpha, 0.23.5
>
> Attachments: MR-4772-0.23.txt, MR-4772-trunk.txt
>
>
> In one particular case we saw a NM go down at just the right time, that most
> of the reducers got the output of the map tasks, but not all of them.
> The ones that failed to get the output reported to the AM rather quickly that
> they could not fetch from the NM, but because the other reducers were still
> running the AM would not relaunch the map task because there weren't more
> than 50% of the running reducers that had reported fetch failures. Then
> because of the exponential back-off for fetches on the reducers it took until
> 1 hour 45 min for the reduce tasks to hit another 10 fetch failures and
> report in again. At that point the other reducers had finished and the job
> relaunched the map task. If the reducers had still been running at 1:45 I
> have no idea how long it would have taken for each of the tasks to get to 30
> fetch failures.
> We need to trigger the map based off of percentage of reducers shuffling, not
> percentage of reducers running, we also need to have a maximum limit of the
> back off, so that we don't ever have the reducer waiting for days to try and
> fetch map output.
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