Hi, Answers inline.
On Mon, Nov 22, 2010 at 11:08 PM, Grandl Robert <[email protected]> wrote: > Thanks all for your comments. > > However, I still have some doubts. > > Basically I can control the number of map/reduce slots with > mapred.tasktracker.map.tasks.maximum > mapred.tasktracker.reduce.tasks.maximum > > but, it is possible to set different number of map/reduce slots for different > slaves ? Yes, this setting is 'tasktracker' specific, as the property name goes. Each TaskTracker can have a different config to load from. > > For example If I am running in a heterogeneous environment, where each slave > have different configuration, it is possible to set different number of slots > based on the specific machine configurations ? Yes, give each machine a unique value via its local copy of mapred-site.xml > For the moment I observed that I can modify only on the master this > parameters, therefore all the nodes will run with same number of map/reduce > slots careless of whatever resources(CPU,MEMORY) offer each other. Not really, your slave machine's config file (conf/mapred-site.xml) needs to reflect the proper settings you need it to use for its TaskTracker (DataNodes have specific configuration as well). -- Harsh J www.harshj.com
