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Hadoop QA commented on HADOOP-1876: ----------------------------------- +1 overall. Here are the results of testing the latest attachment http://issues.apache.org/jira/secure/attachment/12371789/patch1876.txt against trunk revision r604451. @author +1. The patch does not contain any @author tags. javadoc +1. The javadoc tool did not generate any warning messages. javac +1. The applied patch does not generate any new compiler warnings. findbugs +1. The patch does not introduce any new Findbugs warnings. core tests +1. The patch passed core unit tests. contrib tests +1. The patch passed contrib unit tests. Test results: http://lucene.zones.apache.org:8080/hudson/job/Hadoop-Patch/1365/testReport/ Findbugs warnings: http://lucene.zones.apache.org:8080/hudson/job/Hadoop-Patch/1365/artifact/trunk/build/test/findbugs/newPatchFindbugsWarnings.html Checkstyle results: http://lucene.zones.apache.org:8080/hudson/job/Hadoop-Patch/1365/artifact/trunk/build/test/checkstyle-errors.html Console output: http://lucene.zones.apache.org:8080/hudson/job/Hadoop-Patch/1365/console This message is automatically generated. > Persisting completed jobs status > -------------------------------- > > Key: HADOOP-1876 > URL: https://issues.apache.org/jira/browse/HADOOP-1876 > Project: Hadoop > Issue Type: Improvement > Components: mapred > Environment: all > Reporter: Alejandro Abdelnur > Priority: Critical > Fix For: 0.16.0 > > Attachments: patch1876.txt, patch1876.txt > > > Currently the JobTracker keeps information about completed jobs in memory. > This information is flushed from the cache when it has outlived > (#RETIRE_JOB_INTERVAL) or because the limit of completed jobs in memory has > been reach (#MAX_COMPLETE_USER_JOBS_IN_MEMORY). > Also, if the JobTracker is restarted (due to being recycled or due to a > crash) information about completed jobs is lost. > If any of the above scenarios happens before the job information is queried > by a hadoop client (normally the job submitter or a monitoring component) > there is no way to obtain such information. > A way to avoid this is the JobTracker to persist in DFS the completed jobs > information upon job completion. This would be done at the time the job is > moved to the completed jobs queue. Then when querying the JobTracker for > information about a completed job, if it is not found in the memory queue, a > lookup in DFS would be done to retrieve the completed job information. > A directory in DFS (under mapred/system) would be used to persist completed > job information, for each completed job there would be a directory with the > job ID, within that directory all the information about the job: status, > jobprofile, counters and completion events. > A configuration property will indicate for how log persisted job information > should be kept in DFS. After such period it will be cleaned up automatically. > This improvement would not introduce API changes. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.