openx/gen_server_pool — pull request #3 by hirotnk (2014-05-09 06:20:27+00:00)
Title: Use `gen_server:cast/2` to stop worker processes

gen_server_pool can die in the following cases:
1. timeout
2. the worker process has gone for some reason
I have seen these cases happening under the high load.
In addition since it's not checking the return value of
`gen_server_pool_proxy:stop/2`, it looks better to use
`gen_server:cast/2`.