Setting TCP keepalive for Cyrus daemons

[Gary Mills]

I've been noticing idle pop3d processes on our Cyrus front end server
for some time.  These should be transient.  One that was several days
old had an established TCP connection to a wireless client that had
disappeared.  Presumably the client never closed the connection.

Setting TCP keepalive on the file descriptor should permit the kernel
to close the connection in this situation.  Does this sound
reasonable?  Perhaps it's already been addressed in a later Cyrus
version.  We're running cyrus-imapd-2.3.8.

I'm willing to add a `keepalive' option to Cyrus master along with the
setsockopt() system call to enable that setting.  This option could be
added to the cyrus.conf file for any services that could benefit from
it. Would this be a reasonable addition to Cyrus?

-- 
-Gary Mills-        -Unix Group-        -Computer and Network Services-