Re: Query performance degrades over time.

[masarati@aero.polimi.it]

> We are experiencing a decay in query performance over time using
> OpenLDAP 2.3.43 on CentOS 5.
>
> After populating the database with about 70 000 entries, the query
> response time for one entry is about 0.4s. After about two hours the
> same query takes over 1s.  The slapd.conf file and DB_CONFIG files that
> we use can be found at the following URLs.
>
> http://svnweb.cern.ch/trac/gridinfo/browser/bdii/trunk/etc/bdii-slapd.conf
> http://svnweb.cern.ch/trac/gridinfo/browser/bdii/trunk/etc/DB_CONFIG
>
> Does anyone have an idea about what is happening.

Not sure whether it matters or not, but your DB_CONFIG's set_cachesize
looks very small, about 50MB.  Are the same DB_CONFIG settings used for
all databases?  What database, of the 3 defined in your slapd.conf, is
suffering from this problem?  Are critical searches related to indexed
attrs?  Can you reproduce the problem with recent releases (e.g. 2.4.19)?

Also, I note that only in the first database you define an equality index
on objectClass.  This is instrumental for decent performances of slapd, as
documented in slapd-bdb(5) (the presence index on objectClass is
pointless).

p.