RE: Modify performance

["Howard Chu" <hyc@highlandsun.com>]

Upgrade to OpenLDAP 2.1 and use back-bdb. You probably have indexing enabled
for several attributes. In OpenLDAP 2.0, on any modify, all attribute indices
for the entry are recomputed, even if most of those attributes are unchanged.
This generates enough churn that even with dbnosync, the page cache for the
database fills up quickly with dirty pages and needs to be flushed. In
OpenLDAP 2.1 back-bdb, only the indices of modified attributes are updated,
so much less I/O traffic is generated.

  -- Howard Chu
  Chief Architect, Symas Corp.       Director, Highland Sun
  http://www.symas.com               http://highlandsun.com/hyc
  Symas: Premier OpenSource Development and Support

> -----Original Message-----
> From: owner-openldap-software@OpenLDAP.org
> [mailto:owner-openldap-software@OpenLDAP.org]On Behalf Of Ugen

> Good day all!
>
>  I have been using openldap-2.0.27 for some time now.
>
>  With correct settings for dbsync i was able to improve the
> performance
> of add operations significantly. The settings are such that
> all the adds
> go to
> memory cache and it is only synched to the disk once in a while.
>
>  However i don't seem to get any improvement in modify performance -
> it feels as though after processing about 5 entries  (1
> modification per
> entry) the server starts synching to disk after every request.
> It takes close to a minute (or possibly more) to modify about
> 100 entries.
>
>  Is this a normal behavior? How do i remedy this?
> --Ugen
>
>