[Dovecot] Restarting dovecot-auth stops authentication

Attila Nagy bra at fsn.hu
Tue Dec 21 19:37:33 EET 2010

  On 12/21/2010 01:31 PM, Timo Sirainen wrote:
> On 21.12.2010, at 13.51, Attila Nagy wrote:
>> On 11/18/2010 06:45 PM, Timo Sirainen wrote:
>>> On Wed, 2010-11-17 at 21:17 +0100, Attila Nagy wrote:
>>>> pop3-login: Error: net_connect_unix(pop3) failed: Connection refused
>>> Right. This is the main problem. So the question becomes why is the
>>> connection being refused.
>> I would really love to solve this now. :)
>> What connects here to what? pop3-login to the pop3 service?
> Yes. For each login.
Yes, that's clear.
>> service imap-login {
>>   client_limit = 8
> Why imap-login with this small client_limit? The default should be ok (1000).
Because I think that Dovecot's processes block on IO and not just on 
distinct IO operations, but larger tasks, like opening a maildir with a 
lot of e-mails without indexes.
Am I wrong? Or partly wrong, because it uses blocking IO, but it can 
multiplex them, so while one user struggles with the file system to 
build indexes of his maildir, an other client in the same process can 
happily do POP/IMAP stuff?
The rationale is to spread IO (and users) amongst processes, because the 
OS can schedule them concurrently, but don't have too many processes, 
because that eats a lot of memory and other resources.

>> service imap {
>>   client_limit = 8
> This definitely doesn't help. I'm not sure if setting client_limit=1 fixes this problem entirely or not, but try that first.
I've already done experiments with that, but had to switch context and 
forgot the results. Will do again.

More information about the dovecot mailing list