max number of map/reduce per node

[Oleg Ruchovets]

Hi
   I found that my job runs with such parameters:
mapred.tasktracker.map.tasks.maximum    4
mapred.tasktracker.reduce.tasks.maximum    2

   I try to change these parameters from my java code

    Properties properties = new Properties();
    properties.put("mapred.tasktracker.map.tasks.maximum" , "8");
    properties.put("mapred.tasktracker.reduce.tasks.maximum" , "4");

But executing the job I didn't get updated values of these parameters , it
remains:

mapred.tasktracker.map.tasks.maximum 4
mapred.tasktracker.reduce.tasks.maximum 2


Should I change the parameters on hadoop XML configuration files?


Please advice.