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Hadoop QA commented on MAPREDUCE-6166: -------------------------------------- {color:green}+1 overall{color}. Here are the results of testing the latest attachment http://issues.apache.org/jira/secure/attachment/12685168/MAPREDUCE-6166.v3.txt against trunk revision 0653918. {color:green}+1 @author{color}. The patch does not contain any @author tags. {color:green}+1 tests included{color}. The patch appears to include 1 new or modified test files. {color:green}+1 javac{color}. The applied patch does not increase the total number of javac compiler warnings. {color:green}+1 javadoc{color}. There were no new javadoc warning messages. {color:green}+1 eclipse:eclipse{color}. The patch built with eclipse:eclipse. {color:green}+1 findbugs{color}. The patch does not introduce any new Findbugs (version 2.0.3) warnings. {color:green}+1 release audit{color}. The applied patch does not increase the total number of release audit warnings. {color:green}+1 core tests{color}. The patch passed unit tests in hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core. {color:green}+1 contrib tests{color}. The patch passed contrib unit tests. Test results: https://builds.apache.org/job/PreCommit-MAPREDUCE-Build/5060//testReport/ Console output: https://builds.apache.org/job/PreCommit-MAPREDUCE-Build/5060//console This message is automatically generated. > Reducers do not catch bad map output transfers during shuffle if data > shuffled directly to disk > ----------------------------------------------------------------------------------------------- > > Key: MAPREDUCE-6166 > URL: https://issues.apache.org/jira/browse/MAPREDUCE-6166 > Project: Hadoop Map/Reduce > Issue Type: Bug > Components: mrv2 > Affects Versions: 2.6.0 > Reporter: Eric Payne > Assignee: Eric Payne > Attachments: MAPREDUCE-6166.v1.201411221941.txt, > MAPREDUCE-6166.v2.201411251627.txt, MAPREDUCE-6166.v3.txt > > > In very large map/reduce jobs (50000 maps, 2500 reducers), the intermediate > map partition output gets corrupted on disk on the map side. If this > corrupted map output is too large to shuffle in memory, the reducer streams > it to disk without validating the checksum. In jobs this large, it could take > hours before the reducer finally tries to read the corrupted file and fails. > Since retries of the failed reduce attempt will also take hours, this delay > in discovering the failure is multiplied greatly. -- This message was sent by Atlassian JIRA (v6.3.4#6332)