[ https://issues.apache.org/jira/browse/MAPREDUCE-1333?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Allen Wittenauer resolved MAPREDUCE-1333. ----------------------------------------- Resolution: Won't Fix > Parallel running tasks on one single node may slow down the performance > ----------------------------------------------------------------------- > > Key: MAPREDUCE-1333 > URL: https://issues.apache.org/jira/browse/MAPREDUCE-1333 > Project: Hadoop Map/Reduce > Issue Type: Bug > Components: jobtracker, task, tasktracker > Affects Versions: 0.20.1 > Reporter: Zhaoning Zhang > > When I analysis running tasks performance, I found that parallel running > tasks on one single node will not be better performance than the serialized > ones. > We can set mapred.tasktracker.{map|reduce}.tasks.maximum = 1 individually, > but there will be parallel map AND reduce tasks. > And I wonder it's true in the real commercial clusters? -- This message was sent by Atlassian JIRA (v6.2#6252)