Sure, but not the number of tasks running concurrently on a node at the same time.
On Wed, Jun 30, 2010 at 1:57 PM, Ted Yu <[email protected]> wrote: > The number of map tasks is determined by InputSplit. > > On Wednesday, June 30, 2010, Pierre ANCELOT <[email protected]> wrote: > > Hi, > > Okay, so, if I set the 20 by default, I could maybe limit the number of > > concurrent maps per node instead? > > job.setNumReduceTasks exists but I see no equivalent for maps, though I > > think there was a setNumMapTasks before... > > Was it removed? Why? > > Any idea about how to acheive this? > > > > Thank you. > > > > > > On Wed, Jun 30, 2010 at 12:08 PM, Amareshwari Sri Ramadasu < > > [email protected]> wrote: > > > >> Hi Pierre, > >> > >> "mapred.tasktracker.map.tasks.maximum" is a cluster level configuration, > >> cannot be set per job. It is loaded only while bringing up the > TaskTracker. > >> > >> Thanks > >> Amareshwari > >> > >> On 6/30/10 3:05 PM, "Pierre ANCELOT" <[email protected]> wrote: > >> > >> Hi everyone :) > >> There's something I'm probably doing wrong but I can't seem to figure > out > >> what. > >> I have two hadoop programs running one after the other. > >> This is done because they don't have the same needs in term of processor > in > >> memory, so by separating them I optimize each task better. > >> Fact is, I need for the first job on every node > >> mapred.tasktracker.map.tasks.maximum set to 12. > >> For the second task, I need it to be set to 20. > >> so by default I set it to 12 and in the second job's code, I set this: > >> > >> Configuration hadoopConfiguration = new Configuration(); > >> > hadoopConfiguration.setInt("mapred.tasktracker.map.tasks.maximum", > >> 20); > >> > >> But when running the job, instead of having the 20 tasks on each node as > >> expected, I have 12.... > >> Any idea please? > >> > >> Thank you. > >> Pierre. > >> > >> > >> -- > >> http://www.neko-consulting.com > >> Ego sum quis ego servo > >> "Je suis ce que je protège" > >> "I am what I protect" > >> > >> > > > > > > -- > > http://www.neko-consulting.com > > Ego sum quis ego servo > > "Je suis ce que je protège" > > "I am what I protect" > > > -- http://www.neko-consulting.com Ego sum quis ego servo "Je suis ce que je protège" "I am what I protect"
