Re: ldapsearch stalling when performing searches with a large number of results

[Quanah Gibson-Mount <quanah@zimbra.com>]

--On Tuesday, September 25, 2012 2:21 PM +0100 Mark Cairney 
<mark.cairney@ed.ac.uk> wrote:

> Hi,
>
> I've been finding that ldapsearch will freeze when performing searches
> with a large (typically >10,000) number of results. As far as I can tell
> this does not appear to be related to server load as according to iostat
> and top the servers don't appear to be stressed and the servers continue
> to respond to incoming requests.
>
> I'm running OpenLDAP 2.4.30 with BDB 4.8.30 in multi-master mode with
> syncrepl if this makes any difference. I have tried upgrading to 2.4.32
> but  this appears to be exhibiting the same behaviour.
>
> In terms of the size of the database I've got about 300,000 entries and
> my bdb database files are currently taking up 5.6G. The servers
> themselves are 4xquad-cores with 24GB RAM.
>
>
> Has anyone else seen this behaviour or should I file an ITS?

Please provide any tuning that you've done.  It's fairly impossible to 
comment on why you are seeing this behavior without it.

I.e., what are the *cache settings you set in slapd.conf/cn=config?  What 
is the contents of your DB_CONFIG file?  Are you using an shm key?

You may wish to read over 
<https://wiki.zimbra.com/wiki/OpenLDAP_Performance_Tuning>.  You can easily 
map the information there to a non-zimbra installation.

--Quanah

--

Quanah Gibson-Mount
Sr. Member of Technical Staff
Zimbra, Inc
A Division of VMware, Inc.
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