[Dovecot] Dovecot 1.1rc3 "Out of Memory" crashes from pop3-login?

[richs at whidbey.net]

Timo Sirainen wrote:
> On Apr 17, 2008, at 7:36 PM, richs at whidbey.net wrote:
>> Timo Sirainen wrote:
>>> On Apr 17, 2008, at 6:56 PM, richs at whidbey.net wrote:
>>>> We recently began seeing server crashes in our cluster related to 
>>>> "pop3-login", which is causing "oom-killer" to be invoked.  The 
>>>> server only recovers after a reboot.
>>> So oom-killer doesn't solve the issue? Then it's likely it has 
>>> nothing to do with pop3-login, OOM killer just selects a bad target 
>>> to kill (and Dovecot happily restarts a new pop3-login process) while 
>>> the real memory-eating process stays alive. Can you check with ps 
>>> what process(es) are eating all the memory?
>>
>> That's a good point.  Actually, oom-killer does solve the issue 
>> initially, but in every case the server eventually locks up (around 30 
>> minutes later).
>>
>> Unfortunately at this point "ps" and "top" can't run, so we haven't 
>> been able to collect much information.  Here's a complete look at the 
>> "oom-killer" events:
> 
> What do you have login_process_size set to? The default should be 64MB, 
> so unless you changed that a single login process couldn't be able to 
> use up all memory (but all of them at once could, of course). So maybe 
> setting login_process_per_connection=no and 
> login_max_processes_count=(something small) could show something useful.
> 

The login_process_size was commented out, so must've been 64MB.  We'll 
try what you suggested and let you know what we see.  Thanks Timo!

-Rich