[Hadoop-common-user] Override mapred.tasktracker.tasks.maximum?

Hello all

Is it possible for a Hadoop program to override
mapred.tasktracker.tasks.maximum at runtime? I've found that my job
overloads our nodes when running our default 8 tasks per node, but if
I decrease mapred.tasktracker.tasks.maximum in the config file and
restart the cluster it seems to go fine. However, when I tried to set
this parameter in my program it seemed to be ignored. I'd like to set
this at runtime rather than having to restart the cluster. Is this
only read when tasktrackers are started or can I override it?

Thanks!

-steve