in the hadoop-site.xml or hadoop-default.xml file. you can find a parameter: "mapred.map.tasks". Change it value to 3. At the same time set "mapred.tasktracker.map.tasks.maximum" to 3 if you use only one tasktracker.
On Wed, Dec 16, 2009 at 3:26 PM, psdc1978 <psdc1...@gmail.com> wrote: > Hi, > > I would like to have several Map tasks that execute the same tasks. > For example, I've 3 map tasks (M1, M2 and M3) and a 1Gb of input data > to be read by each map. Each map should read the same input data and > send the result to the same Reduce. At the end, the reduce should > produce the same 3 results. > > Put in conf/slaves file 3 instances of the same machine > > <file> > localhost > localhost > localhost > </file> > > does it solve the problem? > > > How I define the number of map tasks to run? > > > > Best regards, > -- > xeon > Chen
