shutdown_clients ignored on Director upgrade/restart

[Tom Sommer]

When yum updates a Dovecot Director, it restarts all processes - however 
a few imap-login and pop3-login processes hang because they are still 
proxying connections.

It's like the now orphaned processes are stalled, and needs a kill -9 to 
die.

This is a problem because those stalled connections are still connected 
to backends, so when new connections are made from the same account, 
they do not end up on the same backend and thus index corruption happens 
(same account, two different backends).

shutdown_clients is enabled but it appears Dovecot restarts regardless 
of verifying all processes/clients are shut down.

Just had this happen upon yum update from dovecot-2.3.11.3-3 to 
dovecot-2.3.11.3-4

-- 
Tom