Interesting - Pauls Reply was blocked by Barracuda-Spamfirewall
Seems this was only a temporary problem
        
Zeit: 2012-01-27 10:05:06                       
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> For a really large database I would not do any storage transition
> initially. New messages will be stored in the new schema, old messages
> are still available

good to know that transition should be painless
database is around 10 GB, i guess not too large

i would shutdwon the mailservices before transition late at night
running on a fat VM with > 10 GB RAM on a VM (HP ProLiant, ESxi 4.1)
backed by a HP MSA SAN should do the job quite fast

> This will break IMAP body searches (who uses those??)

hmm - i do :-)

> As to the connection-pooling: ymmv. PostgreSQL has a different
> sweetspot than MySQL. It depends on the concurrency levels you
> experience

2.2 has currently around 250 mysql-connections
a smaller count would free per-connection-buffers for innodb_buffer-pool

what i am missing are the parameters for connection pooling
the "dbmail.conf" from the last RC-sources looks like the dbmail 2.2.x

AFAIR pooling is only for imap currently and nor for POP3
or am i missing something here?

Thanks and best wishes from vienna
Harry

Am 29.01.2012 22:17, schrieb Thomas Raschbacher:
>  
>  
> ----------------original message-----------------
> From: "Paul J Stevens" 
> To: "DBMail mailinglist" [email protected] 
> Date: Fri, 27 Jan 2012 10:04:59 +0100
> -------------------------------------------------
>  
>  
>> On 01/27/2012 03:28 AM, Reindl Harald wrote:
>>> sounds good and happily you are still alive!
>>>
>>> is there any documentation how transition to "single instance 
>>> storage" works on existing hughe databases and recommended 
>>> configurations for connection-pooling
>>
>> For a really large database I would not do any storage transition
>> initially. New messages will be stored in the new schema, old messages
>> are still available. This will break IMAP body searches (who uses
>> those??), but everything else works just fine.
>>
>> When you feel like everything is working as it should, you may start
>> migrating old content in batches at times when fewer clients are
>> connected.
>>
>> dbmail-util is used for that
>>
>> -M::
>> migrate legacy 2.2.x messageblks to mimeparts table.
>>
>> -m limit::
>> limit number of physmessages migrated. Default 10000 per run.
>>
>> As to the connection-pooling: ymmv. PostgreSQL has a different
>> sweetspot than MySQL. It depends on the concurrency levels you
>> experience. Start low, say at 5 concurrent database connections, and
>> increase only if really necessary.
>>
>> If you use a load-balancing solution using multiple dbmail heads, keep
>> the pool small and keep an eye on 'mysqladmin processlist'.
>>
>> Remember: dbmail can easily handle dozens of concurrently connected
>> mail clients - hundreds if you have fast hardware - and still pipeline
>> all queries through just a few database connectors. Having just a few
>> database connectors running can actually give you better performance
>> under some circumstances since lock contention in the database will be
>> very low.
> 
> 
> nice and easy migration it seems :) I like it.
> 
> Is there a feature list / comparision to 2.x somewhoere?
> 
> Keep up the good work!
> 
> Regards,
>  Thomas R -- a happy dbmail user ;)
> P.S.: @paul: are you still working together with egroupware folks to improve 
> egw email client+dbmail?

-- 

Mit besten Grüßen, Reindl Harald
the lounge interactive design GmbH
A-1060 Vienna, Hofmühlgasse 17
CTO / software-development / cms-solutions
p: +43 (1) 595 3999 33, m: +43 (676) 40 221 40
icq: 154546673, http://www.thelounge.net/

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