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Hadoop QA commented on MAPREDUCE-4469: -------------------------------------- -1 overall. Here are the results of testing the latest attachment http://issues.apache.org/jira/secure/attachment/12544793/MAPREDUCE-4469_rev4.patch against trunk revision . -1 patch. The patch command could not apply the patch. Console output: https://builds.apache.org/job/PreCommit-MAPREDUCE-Build/2846//console This message is automatically generated. > Resource calculation in child tasks is CPU-heavy > ------------------------------------------------ > > Key: MAPREDUCE-4469 > URL: https://issues.apache.org/jira/browse/MAPREDUCE-4469 > Project: Hadoop Map/Reduce > Issue Type: Bug > Components: performance, task > Affects Versions: 1.0.3 > Reporter: Todd Lipcon > Assignee: Ahmed Radwan > Attachments: MAPREDUCE-4469.patch, MAPREDUCE-4469_rev2.patch, > MAPREDUCE-4469_rev3.patch, MAPREDUCE-4469_rev4.patch > > > In doing some benchmarking on a hadoop-1 derived codebase, I noticed that > each of the child tasks was doing a ton of syscalls. Upon stracing, I noticed > that it's spending a lot of time looping through all the files in /proc to > calculate resource usage. > As a test, I added a flag to disable use of the ResourceCalculatorPlugin > within the tasks. On a CPU-bound 500G-sort workload, this improved total job > runtime by about 10% (map slot-seconds by 14%, reduce slot seconds by 8%) -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira