RE: OpenLDAP performance issue

[Igor Brezac <igor@ipass.net>]

On Wed, 30 Apr 2003, Sarah Burke wrote:

> My issue, is that I want to use OpenLDAP as the LDAP front end of an
> application.
> This application will have many different clients, that will connect each
> time they perform an LDAP search.
> More similar to a web server, then a typical LDAP directory.
>
> So it doesn't make sense in my case, to connect once, and then do multiple
> searches on the same connection.
> When I do this, I do see performance improve greatly!
>
> So has anyone ever tried to do this with OpenLDAP?
> Performance seems to degrade greatly when multiple clients are continuously
> trying to connect?

Sure, if you connect thousands of clients to one openldap server the
performance will degrade.  Your machine, OS and Openldap have finite
amount of resources.  Please be more specific.  How many clients? How do
you test the performance?  Is testing client on the same machine as the
openldap server?  ldapsearch utility will not give you accurate results.
I am fairly certail Sun Ultra 60 cannot start ldapsearch more that 30
times per second.

-Igor

> Any help or info appreciated!
>
> Sarah
>
> -----Original Message-----
> From: Quanah Gibson-Mount [mailto:quanah@stanford.edu]
> Sent: Wednesday, April 30, 2003 10:17 AM
> To: openldap-software@OpenLDAP.org
> Subject: RE: OpenLDAP performance issue
>
>
>
>
> --On Wednesday, April 30, 2003 9:30 AM -0400 Sarah Burke
> <sarah.burke@bridgewatersystems.com> wrote:
>
> > This is my setup. I am running Openldap 2.1.6 on a Sun Ultra 60, dual
> > CPU. I configured the software with the "null" backend. This means
> > that no query is actually being performed, the server just errors
> > back. I'm using this case to see what kind of throughput I can get
> > through the OpenLDAP daemon iteself. I have changed nothing in the
> > configure except for enabling the null backend. I start up slapd, and
> > I am using the ldapsearch CLU to send a high load of requests to the
> > server. I can only get about 30 ldapsearch/ sec. Like I said before.
> > Each ldapsearch actually creates a new socket, bind, searches and
> > unbinds. When I look at the slapd process using "top", the process
> > seems to be in sleep state 99% of the time, even under heavy load???
> > Anyone know what is going on??? Thanks, Sarah ps. I will try this test
> > with the lastest OpenLDAP version.
>
> Sarah,
>
> This really won't give you any meaningful performance numbers.  Your rate
> of performance will vary based on many different factors, a large part of
> which is the DB backend you use, your DB cache size, your indexing, etc
> etc.  The method that you use to query the server can also affect your
> results.  I can tell you from my own performance testing of our setup, that
> the ldapsearch binary is a particularly inefficient way to test
> performance.  With the ldapsearch binary, running queries from inside a
> perl script from multiple machines, we get approximately 66 queries/second.
> Using Net::LDAPapi from Cymas, with a single connection that performs
> multiple queries, I get from 220 to 400 queries/second, depending on how I
> structure my search.  Using pooled connections can also greatly increase
> your search rate.  Basically, what you are doing gives you no indication as
> to whether or not you will have the query rate you desire because there are
> so many other factors that influence what your actual query rate will be.
>
> --Quanah
>
> --
> Quanah Gibson-Mount
> Senior Systems Administrator
> ITSS/TSS/Computing Systems
> Stanford University
> GnuPG Public Key: http://www.stanford.edu/~quanah/pgp.html
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-- 
Igor