[ https://issues.apache.org/jira/browse/MAPREDUCE-1533?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Vinod K V updated MAPREDUCE-1533: --------------------------------- Attachment: MAPREDUCE-1533-and-others-20100413.1.txt Patch for Yahoo! distribution. Uploading it on behalf of Amar. Not for commit to any of the apache svn branches. > reduce or remove usage of String.format() usage in > CapacityTaskScheduler.updateQSIObjects > ----------------------------------------------------------------------------------------- > > Key: MAPREDUCE-1533 > URL: https://issues.apache.org/jira/browse/MAPREDUCE-1533 > Project: Hadoop Map/Reduce > Issue Type: Bug > Affects Versions: 0.20.1 > Reporter: Rajesh Balamohan > Assignee: Amar Kamat > Attachments: MAPREDUCE-1533-and-others-20100413.1.txt, > mapreduce-1533-v1.4.patch > > > When short jobs are executed in hadoop with OutOfBandHeardBeat=true, JT > executes heartBeat() method heavily. This internally makes a call to > CapacityTaskScheduler.updateQSIObjects(). > CapacityTaskScheduler.updateQSIObjects(), internally calls String.format() > for setting the job scheduling information. Based on the datastructure size > of "jobQueuesManager" and "queueInfoMap", the number of times String.format() > gets executed becomes very high. String.format() internally does pattern > matching which turns to be out very heavy (This was revealed while profiling > JT. Almost 57% of time was spent in CapacityScheduler.assignTasks(), out of > which String.format() took 46%. > Would it be possible to do String.format() only at the time of invoking > JobInProgress.getSchedulingInfo?. This might reduce the pressure on JT while > processing heartbeats. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: https://issues.apache.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira