Effect of mongrel_rails cluster::restart

Hi,

I am using a mongrel cluster of 3 mongrels behind an nginx server for
deployment.
I am using god to watch the mongrels using mongrel_rails
cluster::restart.

The question I have is when mongrel_rails cluster::restart gets
called,
does it immediately kill the mongrel or does it wait till the requests
the mongrel is currently processing gets rendered or redirected? If
that
is not default behavior, is there a way to do it / even necessary?

Thanks,
Arun