The process count keeps growing!
********************************

If you notice that your imapd process count continues to grow and
never decreases, there are a number of options which may be affecting
it.


1. Reuse count
==============

By default, imapd processes will remain alive for 250 new connections
before shutting down. Setting this to a lower value will reduce the
amount of time unused processes hang around. There is a tradeoff
between startup/shutdown overhead and process longevity.

The use setting is the **- U** argument to imapd(8).


2. Maximum child count
======================

By default, Cyrus is allowed to spawn a limitless number of child
imapd processes. To control this growth, adjust the **maxchild**
option in cyrus.conf(5).


3. Clean up connections that are no longer in use
=================================================

While POP connections are short lived, IMAP connections can be long
lived. And then there are processes trying to listen to a client
that’s no longer alive.

Setting **tcp_keepalive** option in imapd.conf(5) to **1** can be used
to test if connections are still alive. The operating system will send
an ACK packet every so often (every 2 hours by default on Linux) which
tests if the TCP endpoint is still reachable.

The other **tcp_keepalive_** options help control how and when the
test occurs.
