There's heartbeat between jobtracker and tasktracker, namenode and datanode.
Besides, tasktracker will report task progress info to jobtracker, and
datanode will report block report to namenode.
On Fri, Aug 13, 2010 at 7:39 AM, Ahmad Shahzad <[EMAIL PROTECTED]> wrote:
> Hi ALL,
> Can anyone tell me the purpose for RPC server and RPC client
> that is used in hadoop. As far as logs tell, they are used by JobTracker
> TaskTracker, as well as namenode and datanode. Can anyone tell me that for
> what purpose RPC server and client are used by each of them.