Any one know how to control the number of reduce tasks launched by JT to a
certain TT in one heartbeat respond?
In my case, the heartbeat message go back and forth between JT and TT every
3 seconds, and the command to start a reduce is contained in that heartbeat
message. But now only one reduce can be invoked by one heartbeat Respond
from JT although TT has more than one reduce slot.
I hope I can set it, not considering the network bandwidth congestion
caused by it.