Felix, > I'm using the new Job class: > > http://hadoop.apache.org/common/docs/current/api/org/apache/hadoop/mapreduce/Job.html > > There is a way to set the number of reduce tasks: > > setNumReduceTasks(int tasks) > > However, I don't see how to set the number of MAP tasks? > > I tried to set it through mapred-site.xml : > > <property> > <name>mapred.map.tasks</name> > <value>500</value> > </property> > > It doesn't work either (launched map task is still small). > > I'm wondering, do I have to rename the prefix from "mapred" to > "mapreduce"? like this (for all configurations?): > > <property> > <name>mapreduce.map.tasks</name> > <value>500</value> > </property> > > I added both, and it still doesn't work.
As documented in the mapreduce tutorial as well as the Java documentation (http://bit.ly/9HKclu), the number of map tasks is primarily determined by the number of input splits generated for the input data. Thanks Hemanth
