LDAp performance limites to 50 searchs /s?

[Leigh Porter <leighldap@leighporter.org>]

Hiya folks,

I am trying to tune OpenLDAP as best I can on a couple of boxes. All
the attributes I search on are indexed, my cachesize and dbcachesize are
scaled to suit my database and I compiled with TCP_NODELAY and yet I can
not get over a 50 searches a second barrier.

To test I am running simple shell scripts that call ldapsearch, I run say
50 of these on a single box but after about 5-6 instances by search rate on
the ldap box does not go above about 50 per second.

I am using the following query to find the number of operations 
currently recorded
on the ldap monitor database and then running this every second and 
taking a delta,
is this a reasonable way to derive the number of searches per second?

ldapsearch -LLL -x -b "cn=Search,cn=Operations,cn=Monitor" '*' 
monitorOpInitiated

Aside from that, it works fine :)

Thanks folks,
Leigh Porter
Systems Architect