But this is the limit per tasktracker, right? And I have 6 nodes, so 6 tasktrackers, which mean it should go up to 12 tasks?
Take a look at 2.7 here: http://wiki.apache.org/hadoop/FAQ I just tried with the setting below (changing 2 by 6) but I'm getting the same result. JM 2012/10/11 Kevin O'dell <[email protected]>: > J-M, > > It should be in the mapred-site.xml the values > are mapred.tasktracker.map.tasks.maximum and > mapred.tasktracker.reduce.tasks.maximum. This is the default in CDH4 > > <property> > <name>mapreduce.tasktracker.map.tasks.maximum</name> > <value>2</value> > <description>The maximum number of map tasks that will be run > simultaneously by a task tracker. > </description> > </property> > > <property> > <name>mapreduce.tasktracker.reduce.tasks.maximum</name> > <value>2</value> > <description>The maximum number of reduce tasks that will be run > simultaneously by a task tracker. > </description> > </property> > > This would explain why they are going 2 by 2. Does this help? > > On Thu, Oct 11, 2012 at 4:25 PM, Jean-Marc Spaggiari < > [email protected]> wrote: > >> I don't know. I did not touched that. Where can I found this information? >> >> 2012/10/11 Kevin O'dell <[email protected]>: >> > What are you max tasks set to? >> > >> > On Thu, Oct 11, 2012 at 3:59 PM, Jean-Marc Spaggiari < >> > [email protected]> wrote: >> > >> >> Hi, >> >> >> >> Is there a way to force the number of map tasks in a MR? >> >> >> >> I have a 25 regions table splitted over 6 nodes. But the MR is running >> >> the tasks only 2 by 2. >> >> >> >> Is there a way to force it to run one task on each regionserver >> >> serving at least one region? Why is the MR waiting for 2 taskes to >> >> complete before sending to the other tasks? >> >> >> >> I'm starting the MR with a caching of 100. >> >> >> >> I tried mapred.map.tasks and speculative=false with no success. >> >> >> >> Any idea how I can increase it this number of tasks? >> >> >> >> Thanks, >> >> >> >> JM >> >> >> > >> > >> > >> > -- >> > Kevin O'Dell >> > Customer Operations Engineer, Cloudera >> > > > > -- > Kevin O'Dell > Customer Operations Engineer, Cloudera
