[Dovecot] imap-login crashes after upgrade to Dovecot 1.2.8 Linux 64-bit

[Chris Wakelin]

On 18/12/2009 01:11, Timo Sirainen wrote:
> On Dec 17, 2009, at 8:01 PM, Chris Wakelin wrote:
> 
>>> Dec 18 00:27:58 imap-login: Info: Disconnected: Connection queue full (auth failed, 1 attempts): user=<user0>, method=PLAIN, rip=<ip0>, lip=134.225.32.156, TLS
>>> Dec 18 00:27:58 imap-login: Panic: file ioloop.c: line 39 (io_add): assertion failed: (fd >= 0)
> 
> I guess the crash is caused by the "connection queue full". I'll see about fixing the crash, but you shouldn't let it get full in any case. So increase your login_max_connections value.
> 

That's puzzling, I thought it was supposed to fire up another imap-login
process (up to login_max_processes_count)? We have something in the
region of 1000 concurrent connections and login_max_processes_count *
login_max_connections = 128 * 256 should be enough for 32000+ of them!

Would it be better to have login_max_connections = 1024 (or even higher)?

I'm also confused as to why we never saw the problem on the Solaris box
(with more connections as it was during term time).

At the moment I'm running with "login_process_per_connection = yes" but
I'm a little concerned about the increased CPU load (I could probably
add more virtual CPUs, but there are apparently some issues with 64-lit
Linux on multiple CPUs in VMWare ESX 3.5.x).

Best Wishes,
Chris

-- 
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Christopher Wakelin,                           c.d.wakelin at reading.ac.uk
IT Services Centre, The University of Reading,  Tel: +44 (0)118 378 8439
Whiteknights, Reading, RG6 2AF, UK              Fax: +44 (0)118 975 3094