[Date Prev][Date Next] [Chronological] [Thread] [Top]

Re: question about ldap performance

man, 2002-11-11 kl. 03:00 skrev Liu Jinhui:

> Now I am setting a smtp system (postfix) which need to process
> query on ldap-server. During the test , I found that when there 
> are simultaneously 200 queries on the ldap server, the query will
> be very slow. I have to made the timeout of ldap query to 60 
> seconds in postfix. But it is too slow that  sending a letter need
> too long time.

I can only report on Exim smtp and full ldap services for AUTH, aliases,
virtual domains etc.

1: Howard Chu has said that to boost LDAP performance with loads way
above yours, cut out logging and reduce regex ACLs to a minimum;

2: On Red Hat 7.2 with Exim 4.10-8 I find no penalty for ldap use
whatsoever, even though Exim on my machine uses ldaps (SSL, not TLS
except for esmtp AUTH) for all of the above (runs parallel
deliveries/emissions). Even though I have to cut out (all including the
latest Red Hat) nscd on my machine, since it eventually kills ldap for
some reason or another.

>    I tried to used anonymous no-bind access the ldap to reduce
> the load on ldap server.

Has *no* measurable effect with Exim and would be impossible for AUTH
esmtp, which I use, anyway.

> I also tried to enlarged the cache in 
> ldapserver.And because I have two smtp server, I set up a local 
> slave ldap in each of the server and  point postfix ldap lookups 
> to the local host. But it couldn't solve the problem. It seems 
> that the ldap query becomes the bottleneck of the mail
> system.

Again some really large orgs (major universities in different countries,
ISPs etc) are running Exim for extremely large accounts, mostly on
Solaris, and ldap is *no* bottleneck. On the other hand, things like
virus and spam checking =are= bottlenecks.

Can only hope this helps. Maybe Sendmail and Qmail people can add their




Tony Earnshaw

So mangt eit ord kunde vori usagt.

e-post:		tonni@billy.demon.nl
www:		http://www.billy.demon.nl