Which webserver to use in production?

matt - thanks for the input.

when mongrel restarts, does it do it gracefully and separately? for
instance, if you have 3 mongrel processes for your app and you do a
restart,
does it kill one (one the client’s connection is dead), restart it with
the
new code and then continue to the next mongrel process? that way you’d
never have a totally dead system. if it waits till all 3 processes are
down
before restarting, there could be some considerable downtime.