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