[Kolab-devel] Re: OpenLDAP performance issues

[Dieter Kluenter]

Hi,

Martin Konold <martin.konold at erfrakon.de> writes:

> Am Montag, 9. Mai 2005 16:50 schrieb Bernhard Reiter:
>
> Hi Dieter,
>
>> > By adding a DB_CONFIG[1] file to /kolab/var/openldap/openldap-data and
>> > adding 'idlecachesize 3000' to slapd.conf performance of slapd could
>> > be increased.
>
>> We already have DB_CONFIG file in the upcoming server release.
>> It does not contain idecachesize, though.

idlecachsize is an option in slapd.conf
>
> Can you please report your results for RC1? 

OK I will update next wekend

> How much better does the performance get with the RC1 settings?
>
> Can you propose better DB_CONFIG values?

The DB_CONFIG settings are heavily depending on the individual system
requirements, that is ram available, disc performance, filesystem
etc. but as a rule of thumb: number of entries x 4KB + 25%, while 4KB is
the average size of an entry plus 25% overhead for operations.
If possible, that is one has 2 ore more SCSI discs, the logfiles may
be moved to the second disc. For parameters see
http://www.openldap.org/faq/data/cache/893.html
If plenty of memory is available, the whole database could be run in shared
memory space, see man slapd-bdb.conf(5) option shm_key. 
Please note that with forthcoming OpenLDAP-2.3 things will change,
most options may be configured and changed at runtime via a
configuration backend.
>
> In general 5000 mails in 68 minutes looks too slow to me and my simple tests 
> show better results.

Right, that's what I wanted to tell.

>> > An anonymous bind of nobody would reduce the number of searches, as
>> > each bind requires two search operations.
>
> You mean for the postfix lookups?

Yes, if security considerations will allow an anonymous bind.

-Dieter
 
-- 
Dieter Klünter | Systemberatung
http://www.dkluenter.de
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