The number of map and reduce slots on each TaskTracker node is controlled by the *mapreduce.tasktracker.map.tasks.maximum*and *mapreduce.tasktracker.reduce.tasks.maximum* Hadoop properties in the mapred-site.xml file. If you change these settings, restart all of the TaskTracker nodes.
I guess you can't change these settings for a specific job through a -D parameter, since you'll need to restart the tasktracker. 2014-05-26 21:52 GMT-03:00 Du Lam <[email protected]>: > is there any setting that can set on run time of job for maximum mapper > concurrently running ? > > i know there is a jobtracker level parameter that can be set, but that > will be global parameter for every job. Is it possible to set per job ? >
