[Feature Request] Multiprocess support

[silvanheller]

Currently, it is not possible to process data / run requests in parallel. You get the following output:

E0307 19:05:53.169884888  518167 fork_posix.cc:70]           Fork support is only compatible with the epoll1 and poll polling strategies 

and this seems to be a known issue: https://stackoverflow.com/questions/55710628/python-process-calling-grpc-server-gets-stuck-and-terminates-unexpectedly

We'd probably want to write some tests which provoke a race condition and see if there's things we can do to support multiprocessing.