[Dovecot] Auth Issues - Urgent - Help!

[David Cunningham]

I agree.  In fact, I may have found a DNS issue that may have been  
causing login sessions to hang and thus reach max too quickly.  The  
last few hours have been stable.  So, I am keeping my fingers crossed.

I have also recompiled dovecot and changed the setting in db-ldap.h  
that reads:

#define DB_LDAP_MAX_QUEUE_SIZE 1024

to

#define DB_LDAP_MAX_QUEUE_SIZE 8192

I have not implemented this change yet as the system has been stable  
for a few hours.  If it happens again, I will implement this change  
which will hopefully allow my queued logins to reach 8192, rather than  
1024, before crashing.

I have considered IMAPproxy.  This will likely make things better, but  
will also not fix the underlying issue.

Plus, I am a bit worried about leaving about 5000 imap sessions open  
on my server at one time.  It's a bit scary.  Any opinions on this?

Dave

Quoting Jakob Hirsch <jh at plonk.de>:

> David Cunningham wrote:
>
>> I have about 5 Thousand users using horde that login ever 1-5   
>> minutes to refresh their page.  I assume it is a setting, but I am   
>> confused as to
>
> This may not related to the real reason of your problem, but I
> recommend  up-imapproxy (http://www.imapproxy.org/) for such setups,
> which caches connections (and therefore logins). You could try to
> enable dovecot's auth_cache instead.