idled multiplying and consuming the server

[Eugene M. Zheganin]

Hi.

Recently I've upgraded one of my servers to cyrus-imapd 2.5.x, and
shortly after upgrade I notices that logs are filling with errors like

Jun 10 19:48:03 ns imap[13392]: IDLE: error sending message DONE to
idled for mailbox user.foobar.Sent: Connection refused.

I was not using idled on 2.4.x. Okay, then I decided that the easiest
way would be to enable idled, so I added the following line to the
cyrus.conf:

idled cmd="idled" listen="/var/imap/socket/idled" proto="udp" prefork=0

The error message was gone, but I noticed immediately that the number of
idled processes was constantly increasing and at some point they
overwhelmed the server. The only thing I had to do is to disable it
back. I tried to add the maxchild=5 option, but it didn't help. What was
I doimng wrong ? Is there some way to limit the number od idled
processes (this server only has 160 mailboxes) or switch back to the old
non-idled behavior ?

Thanks.
Eugene.