We have some vizd cores in the State Machine Stats Update code.
On these machines, redis was down and this was causing continuous
reconnection of generators.
It seems that the generator state machines were deleted (by the lifetime actor task)
while sandesh receive was being processed (by the sandesh state machine task)

The solution is to set task policies and make these tasks exclusive.
Merge pull request #27 from Juniper/anishm_lifetime

We have some vizd cores in the State Machine Stats Update code.