lots of write slowing down searches

[Patrick Radtke <phr2101@columbia.edu>]

Hello,

We have some software that occasionally likes to make lots of 
modifications and adds to OpenLDAP in a short amount of time (5 
modification per sec for a period of 10 minutes).

When ever this happens all ldapsearches become very slow (servers 
handle about 16 searches per second normally). They take upwards of 2 
seconds where previously the were taking 0.05s to answer requests. This 
causes us various problems with log-ins and email lookups.

We are running 2.1.30, but I ran tests on 2.2.19 and had the same 
issues.
we use lbdm as our backend and our indexes are for the standard stuff 
for unix accounts and groups

I understand that OpenLDAP is read optimized but I am wondering if 
switching to BDB would provide significantly better search speeds when 
writes are occurring (ie enough to solve the problem)?

The reasons we haven't switched to BDB so far is that it takes extra 
time to build, setup and tune, and I haven't had much extra time:)

We are planning on fixing our misbehaving software but are just 
concerned that the next time a program does too many writes, everything 
will grind to a halt.


thanks,

Patrick Radtke