Re: Maximum size of the database.

["matthew sporleder" <msporleder@gmail.com>]

On 8/11/07, Howard Chu <hyc@symas.com> wrote:
> Sumith Narayanan wrote:
> > Hi Group,
> >
> > We have a coorporate openldap database in production which has more
> > than 4 million entries. The slapd process serves three different
> > physical dabases of sizes 4 GB , 12 GB and 24 GB respecievely.
> > Earlier it was runnning in ldab backend and was crashing once in 3 -4
> > days. We upgraded to OpenLDAP 2.3.27 and BDB backend 4.4.20. Mac OS
> > Tiger with 4GB RAM in the master and 8 GB ram in the slave. Now it
> > crashes often may be couple of times in a day or sometimes once in 2
> > days. There is nothing much written in the log files but at times it
> > shows out of memory exception. However , the search performance is
> > still good.
> >
> >
> > - What is the maximum size of the database that OpenLDAP can support ?
> > - What is the maxmum number of dns it can hold ?
> > - Is there any solution for the above problem ?
>
> For a machine with 4GB of RAM I think it will max out at around 1-2 million
> DNs. Unfortunately there is no way to control the size of the DN cache in
> OpenLDAP 2.3, it simply grows without bound. A config keyword for the DN cache
> will be in OpenLDAP 2.4.
> --

This is news to me.  Is there a discussion somewhere of the different
caches in openldap/bdb, which ones are tunable and which ones are not?

Could we get an idea with the bdb cache (DB_CONFIG) were set to the
lowest values calculated from db_stat and (FAQ) "How do I determine
the proper BDB/HDB database cache size?" and then working out a
slapd.conf cachesize/idlcachesize?