Adding on to Chen's response. This is a setting meant at Task Tracker level(environment setting based on parameters like your CPU cores, memory etc) and you need to override the same at each task tracker's mapred-site.xml and restart the TT daemon for changes to be in effect.
Regards Bejoy K S From handheld, Please excuse typos. -----Original Message----- From: Chen He <airb...@gmail.com> Date: Fri, 9 Mar 2012 20:16:23 To: <common-user@hadoop.apache.org> Reply-To: common-user@hadoop.apache.org Subject: Re: mapred.tasktracker.map.tasks.maximum not working you set the " mapred.tasktracker.map.tasks.maximum " in your job means nothing. Because Hadoop mapreduce platform only checks this parameter when it starts. This is a system configuration. You need to set it in your conf/mapred-site.xml file and restart your hadoop mapreduce. On Fri, Mar 9, 2012 at 7:32 PM, Mohit Anchlia <mohitanch...@gmail.com>wrote: > I have mapred.tasktracker.map.tasks.maximum set to 2 in my job and I have 5 > nodes. I was expecting this to have only 10 concurrent jobs. But I have 30 > mappers running. Does hadoop ignores this setting when supplied from the > job? >
