Re: What are the correct values for concurrency and threads for the ldbm backend ?

[Quanah Gibson-Mount <quanah@stanford.edu>]

--On Thursday, April 28, 2005 6:37 PM +0200 Pantelis Petridis 
<pantelis.petridis@marconi.com> wrote:

> Hello ,
>
> I am using openldap 2.0.25.
> The reason why I use such an old release is that until now we had no
> reason to upgrade to a newer version.
>
> For performance reasons I had to increase the parameters concurreny to 512
> and threads to 384.
> The ldap backend I use is ldbm. I have about 100000 entries and the
> dabasesize is about  400MB.
> I have a big hpux workstation with 4 processors and 4GB Ram.
> I have to serve 160 read request per second (I can do that when I set
> concurrency to 512 and threads to 384).
>
> The slapd process consumes a lot of memory (more than 1GB) . I can not
> understand why. The database
> is only 400MB even if loaded in memory it is less than 1GB.
>
> Does someone understand why the slapd process uses so much memory ?
> Should I reduce concurrency and threads in the slapd.conf file ?

I will note that OpenLDAP 2.1 was a few hundred times faster than OpenLDAP 
2.0, and that OpenLDAP 2.2 was about 50% faster than OpenLDAP 2.1.  So if 
performance is your issue, I'd recommend upgrading.

Setting a large thread value is generally detrimental to performance.  It 
takes careful experimentation, and I've never found anything over 30 to be 
of any good.

--Quanah

--
Quanah Gibson-Mount
Principal Software Developer
ITSS/Shared Services
Stanford University
GnuPG Public Key: http://www.stanford.edu/~quanah/pgp.html

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