Not true, take a look at my prev. response. On Oct 30, 2012, at 9:08 AM, lohit wrote:
> As far as I recall this is not possible. Per job or per user configurations > like these are little difficult in existing version. > What you could try is to set max map per job to be say half of cluster > capacity. (This is possible with FairSchedule, I do not know of > CapacityScheduler) > For eg, if you have 10 nodes with 4 slots each. You would create pool and set > max maps to be 20. > JobTracker will try its best to spread tasks across nodes provided they are > empty slots. But again, this is not guaranteed. > > > 2012/10/30 Marco Zühlke <[email protected]> > Hi, > > on our cluster our jobs usually satisfied with less than 2 GB of heap space. > so we have on our 8 GB computers 3 maps maximum and on our 16 GB > computers 4 maps maximum (we only have quad core CPUs and to have > memory left for reducers). This works very well. > > But now we have a new kind of jobs. Each mapper requires at lest 4 GB > of heap space. > > Is it possible to limit the number of tasks (mapper) per computer to 1 or 2 > for > these kinds of jobs ? > > Regards, > Marco > > > > > -- > Have a Nice Day! > Lohit -- Arun C. Murthy Hortonworks Inc. http://hortonworks.com/
