Re: 2.2.15 MASSIVE performance problems with proxycache enabled

[Howard Chu <hyc@symas.com>]

Andre Konopka wrote:

> Hi,
>
> with the help of this list I configured a LDAP Proxy Server with 
> overlay proxycache. My aim is to speed up Netscape/Outlook Address 
> Book access.
>
> First I was really impressed about the increasing performance...
> But I found that if you query the LDAP-Server with just a few parallel 
> queries slapd is only updating his cache and doesn't answer any 
> further questions.
>
> How to reproduce...
>
> Just open Netscape Addressbook and enter a single character in the 
> search field. Normally you get back around 100 entries.
> The next time you enter the same letter, say 'a', you can see how fast 
> the answer is available. Now try the same with 'b', 'c' and so on. 
> Very soon you will see that slapd gives you no answer anymore. If you 
> are patient enough you will see that slapd comes back after 5-10 
> minutes or so...
>
> Here ist the slapd.conf
>
>
> allow bind_v2
> database ldap
> lastmod off
> suffix "c=de"
> uri "ldap://x3se.presse-data.de:389/";
> rootdn "cn=root,c=de"
> overlay proxycache
>
> proxyCache bdb 1000000 2 1000 100
>
> cachesize 500
> checkpoint 64 5
> directory /opt/pdldap/openldap/var/openldap-data
> index objectClass eq
> index cn,sn,givenName,mail pres,eq,sub
>
> What's wrong?

You have configured the proxycache to use back-bdb but you have not 
properly configured the back-bdb parameters. You've chosen 1000000 
entries for the size of the proxycache but only 500 entries for the 
back-bdb entry cache. Most likely you haven't set up a proper DB_CONFIG 
either. You're probably also checkpointing too frequently, which is also 
slowing down the server because you're flushing the BDB cache all the time.

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