Re: SLOW Performance: OpenLDAP on Linux and IBM Dual Xeon?

[Donn Cave <donn@u.washington.edu>]

On Wednesday, April 14, 2004, at 02:21 PM, Digant Kasundra wrote:
> I am using OpenLDAP 2.2.8 with BDB 4.2.52, heimdal 0.6, and cyrus-sasl
> 2.1.18.  All machines are on the same kernel with the same cache size
> setups, same dataset, and the tests query the same uids.  The most 
> bizarre
> part is that my Dell Dual Xeon 2.8 Ghz is only able to do 5000 queries 
> a
> mere 10 seconds faster than my Pentium 3 700Mhz.  And my IBM Dual Xeon
> 2.0Ghz comes in last, taking almost 3 times longer.
>
> I need to see if this is an OpenLDAP specific problem or a general 
> system
> problem, as mentioned.  My HTTPD tests showed equal performance and was
> therefore inconclusive.  Is there another test suite I could try?

I had a host here that was a couple of orders of magnitude
slower than it ought to have been, oddly enough also a dual
Xeon.  In my case, all are new HP hardware, but only this
one is dual - though they're all running an smp kernel build.

I still don't known why, but it isn't a major priority since
it never was intended to run a directory anyway.  The next
thing I am going to fix is syslog configuration - the fast
hosts route local4 network, the slow one to disk.  There are
a lot of little things that can be different, and somewhere
in there we may have a performance issue.

During your tests, is there a significant percentage of I/O
wait time?  (As "top" would report, or vmstat's "wa" column.)

	Donn Cave, donn@u.washington.edu