you can manage the number of map tasks by node mapred.tasktracker.map.tasks.maximum=1
On Fri, May 7, 2010 at 9:53 AM, gabriele renzi <rff....@gmail.com> wrote: > On Fri, May 7, 2010 at 2:44 PM, Jonathan Ellis <jbel...@gmail.com> wrote: >> Sounds like you need to configure Hadoop to not create a whole bunch >> of Map tasks at once > > interesting, from a quick check it seems there are a dozen threads running. > Yet , setNumMapTasks seems to be deprecated (together with JobConf) > and while I guess > -Dmapred.map.tasks=N > may still work, it seems that so it seems the only way to manage the > number of map tasks is via a custom subclass of > ColumnFamilyInputFormat. > > But of course you have a point that in a single box this does not add > anything. > -- /* Joe Stein http://www.linkedin.com/in/charmalloc */
