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.
> currently i find the wiki a little unrelieable because it is often
> not ckear what are wishes, what is really changed and what does
> changes mean for existing setups from the view of optimized
> configuration and transition without collateral damage for existing
> messages
Yes, the wiki is seriously lacking some love. I just don't have the
time it needs.
--
________________________________________________________________
Paul J Stevens pjstevns @ gmail, twitter, skype, linkedin
* Premium Hosting Services and Web Application Consultancy *
www.nfg.nl/[email protected]/+31.85.877.99.97
________________________________________________________________
_______________________________________________
DBmail mailing list
[email protected]
http://mailman.fastxs.nl/cgi-bin/mailman/listinfo/dbmail
