[ https://issues.apache.org/jira/browse/MAPREDUCE-1859?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Allen Wittenauer resolved MAPREDUCE-1859. ----------------------------------------- Resolution: Won't Fix Closing as won't fix. With YARN, you don't need to do these types of operations in MR anymore. > maxConcurrentMapTask & maxConcurrentReduceTask per job > ------------------------------------------------------ > > Key: MAPREDUCE-1859 > URL: https://issues.apache.org/jira/browse/MAPREDUCE-1859 > Project: Hadoop Map/Reduce > Issue Type: New Feature > Components: job submission > Affects Versions: 0.20.2 > Reporter: Johannes Zillmann > > It would be valuable if one could specify the max number of map/reduce slots > which should be used for a given job. An example would be an map-reduce job > importing from a database where you don't want 50 map tasks querying one db > at a time but also you don't want to shrink the overall map task count. > Also this is probably already possible through Fair/Capacity-Scheduler or an > own Extension i think it would be a good addition for the default > TaskScheduler since this seems to be more then a rare used feature. > This would have the benefit in situations where you don't have > control/ownership over the cluster as well. > And its more job-centric whereas the existing scheduler extensions seems to > be more job-type-centric. > Implementing this feature should be relatively straightforward. Adding > something like jobConf.setMaxConcurrentMapTask(int) and respecting this > configuration in JobQueueTaskScheduler. > Not sure if this feature would be harmonical with the existing > Fair/Capacity-Schedulers. -- This message was sent by Atlassian JIRA (v6.2#6252)