Cyrus lagging accepting IMAP connections

[Blake Hudson]

Cyrus could lag at this stage if there is a problem reversing its own
IP. With the 'listen' argument specified as is, I would think it would
be reversing 127.0.0.1 (or possibly the main IP on the box?). Make sure
that you have both of these IPs specified in the hosts file. Also make
sure that your clients have reverse DNS (if this is under your control)
and that you have only 2 nearby DNS servers specified in
/etc/resolv.conf and that they both respond quickly.


I assume you're using the default file types for cyrus db's (specified
in imapd.conf) and that if you are using sql for authentication you are
not out of sql connections.

-Blake


Rick Kunkel wrote:
> Hello all,
>
> I'm new to Cyrus.  Historically, I've used Qpopper, Sendmail, and UW IMAP. 
> We recently switched to Cyrus for IMAP.  It came highly recommended...
>
> We've got this on a darned burly machine, running some very recent version 
> of Debian, with a fast CPU, 4GB RAM, and fast SAS drives.  When testing 
> the thing, before it went into production, everything worked awesomely. 
> However, having loaded it with 2300 users, it's suddenly acting 
> erratically.  (Incidentally, of the 2300 users, almost all are POP users, 
> which seems to be working fine.  A few hundred -- at most -- are IMAP, and 
> they are split between squirrelmail users and a handful that use standard 
> MUAs.)
>
> The server acts as if it's low on resources or something, or has hit some 
> kind of connection limit.  It's speedy as heck WHEN it does it what's it's 
> supposed to, but that initial connection is sketchy.  For the first 30 
> seconds after you restart it, it's generally good, but it goes downhill 
> from there.
>
> Testing with telnet exhibits this behavior.  Here's a sample session...
>
> # telnet mail 143
> Trying xxx.xxx.xxx.xxx...
> Connected to mail.
> Escape character is '^]'.
>
>
> And then it just kinda sits.  Sometimes, after 30 seconds or so
>
> * OK mail Cyrus IMAP4 v2.2.13-Debian-2.2.13-10 server ready
>
>
> We're currently using the following line in cyrus.conf for imapd:
>
> imap	cmd="imapd" listen="imap" prefork=1
>
>
> We've messed with tons of different settings here, to little avail.
>
> There don't seem to be any salient log entries.
>
> Anyone have any ideas?
>
> Thanks,
>
> Rick Kunkel
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