Cyrus infrastructure performance less than expected

[Eric Déchaux]

Robert Banz a écrit :
>> I don't have any system log that complains about something and the  
>> only
>> Cyrus message I got is a DB4 warning about lockers. I think the DB4 in
>> question is the TLS sessions cache DB and in my case the number of
>> lockers can be as high as 8 000...
>>     
>
> Dump Berkeley DB with a quickness, and switch to skiplist.
>   

Switching to skiplist gave us great improvements : The first one is the 
memory footprint. We now use around 1.1 Mb per proxyd process instead of 
1.5 to 2 Mb with berkeley. The second one is the load of concurrent 
sessions is much smoother and we dont have the "DB4 lockers" warning 
message anymore.

We also corrected some useless and stupid logging rules set in syslog.conf.

With 5 500 concurrent sessions, frontends still have 1.5 Gb RAM but has 
a rather high runqueue of around 50.

We will now add mail sending with postal to our load test which, for 
now, only concentrate on openning an IMAPS session and selecting mailboxes.


Thanks.
--
Eric