[Kolab-devel] Z-push optimization

[Jeroen van Meeuwen (Kolab Systems)]

Martin Konold wrote:
> Am Freitag 01 Oktober 2010, 21:44:18 schrieb Jeroen van Meeuwen (Kolab
> Systems):
> 
> Hi,
> 
> > I understand this to result in great performance penalties, and hence I
> > was thinking the following scenario might make sense to pursue for the
> > future;
> > 
> > If Cyrus were enabled to keep it's mailboxes.db, annotations.db, seen.db,
> > and possibly even it's .index, .cache and .header in a true SQL database
> > backend, Kolab_Z-Push would be able to use Cyrus' SQL backend as if it
> > were cache.
> > 
> > I've got several threads going on this approach already, so please let me
> > know what you think of using Cyrus' "live" as your "cache".
> 
> Sorry, but using a SQL db as backend for cyrus dbs is simply broken as
> hell. Please don't do that.
> 

This type of "argument" doesn't help any of us.

> It is plain wrong trying to gain performance for some use case by crippling
> the performance of the main use case.
> 

Adding a database backend does not cripple anything. Again, this type of 
"argument" doesn't help any of us.

> On the other hand if you know which kind of information Kolab_Z-Push needs
> you may obtain it much simpler and faster without the extra penality
> directly from the cyrus dbs.
> 

It'd require Kolab_Z-Push to have access to the metadata partition file 
system, and so provides another (significant) trade-off.

> E.g. the access to Berkeley DB can be integrated savely into Kolab_Z-Push
> including proper locking if required.
> 
> Going this route means get even faster data access for Kolab_Z-Push while
> not crippling the common case.
> 
> Yours,
> -- martin
> P.S.: There are very valid reasons why cyrus, postfix etc. use non-sql dbs!
> 

The SQL backend was introduced with cyrus-imapd-2.3.12. There are *very* 
specific, valid reasons why. Postfix allows SQL server backends to be used, 
and there are *very* specific reasons why.

*None* of it has to do anything with the OP though.

Kind regards,

-- 
Jeroen van Meeuwen
Senior Engineer, Kolab Systems AG

e: vanmeeuwen at kolabsys.com
t: +316 42 801 403
w: http://www.kolabsys.com

pgp: 9342 BF08