LDAP Performance

[Dax Kelson]

On Wed, 2003-07-23 at 17:23, seth vidal wrote:
> On Wed, 2003-07-23 at 12:15, Stephen Smoogen wrote:
> > We found that turning on nscd with openldap w/db4 had the speeds
> > equivalent to NIS. However our ldap tables may just be lucky enough to
> > be fast.
> 
> And to be fair - I found that it helps ldap too. but then you suffer
> nscd's problems of over-caching passwords with other uid information.

OpenLDAP can perform massively different depending on how it tuned. 
Even to the order of 10x - 40x difference in performance.

OpenLDAP 2.1 uses Berkeley DB v4 backend by default. So alot of the
performance tuning is really "Berkeley DB tuning", mostly in the realm
of getting the DB cache size set appropriately.

Seriously, you can get very good performance out of OpenLDAP.

This tuning is NOT done inside of the OpenLDAP configuration, but at the
Berkeley DB level.

You need to create a DB_CONFIG file inside of your database directory
(/var/lib/ldap on RHL). If you crank up the size of the shared memory
buffer pool you'll be happy. The default is 256KB!

Go read:

http://www.sleepycat.com/docs/ref/am_conf/cachesize.html
http://www.sleepycat.com/docs/api_c/env_set_cachesize.html
http://www.openldap.org/faq/data/cache/190.html