[ https://issues.apache.org/jira/browse/MAPREDUCE-4469?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13433338#comment-13433338 ]
Alejandro Abdelnur commented on MAPREDUCE-4469: ----------------------------------------------- Ahmed, your suggested approach means that in the case of streaming jobs we may lose the info for up to 9 updates (default), right? > 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 > > > 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: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira