Re: Upgrade from OpenLDAP 2.1.30 -> 2.3.37

["Buchan Milne" <bgmilne@gmail.com>]

On 7/31/07, Leon de Rooij <leon@scarlet-internet.nl> wrote:
> Hi all,
>
> After a period of testing I upgraded our LDAP servers from 2.1.30 to
> 2.3.37. Many things were done, changed replication from slurpd to
> syncrepl, changed backend from ldbm to hdb, even changed the structure
> of the tree a bit, almost everything works great :)
>
> Except some searches are slower !
>
> I have around 160K dn's with around 3.2M attrs in a server with 4G
> memory with a tree looking like this (simplified):


> I have indexed o, ou and namespace with pres and eq (and mail with pres,
> eq and sub), so I don't see a problem there. I still have to look a bit
> more into DB_CONFIG tuning, but still, is it normal behaviour of
> OpenLDAP 2.3.37 with hdb backend that searches in a subtree are slower
> than in the base of the tree ?

With a relatively large database, tuning can have quite a big impact
on behaviour (if the directory is busy). You really need to provide
information on what tuning you have done (both in DB_CONFIG, and with
cachesize and idlcachesize for this database in slapd.conf). You most
likely need at least 100MB cachesize set in DB_CONFIG ... and hdb
likes at least 3* idlcachesize as (entry) cachesize (as discussed in
the slapd-hdb man page).

Regards,
Buchan