Hi,
I'm (still) evaluating dovecot for a switch from UW in the near future. All the following happens on a Solaris server.
Functionally, all is well. However, I see strange phenomena.
Normally, dovecot is pretty swift. Every now and then, though, things slow down to a crawl. Everything seems to be working, still, but a few orders of magnitude slower. A copy of an outgoing message (of a few lines) to my Out box, which normally succeeds nearly instantly, suddenly takes over 30 minutes, for example.
Obvious things to look for would be conflicting locking strategies. As far as I know, though, my mail delivery agent (procmail) and all mail handling software use dotlocking, fcntl lockf, in that order), as does dovecot.
In syslog there's nothing to see, except an occasional
SSL_accept() syscall failed: EOFmesssage, which I can correlate to my service monitoring software (nagios), which checks for the presence of the imaps service.
When this happens and I quit my mail agent (Thunderbird), an imap process seems to remain on the server. Killing that does not resolve the extreme slowdown; that persists on consecitive reruns of my mailer.
I'm at a loss here. Any hints?