Re: Casual benchmarking OS performace with OpenLDAP

[Howard Chu <hyc@symas.com>]

Certainly it seems something fishy is going on here, but it's hard to tell.

James F. Hranicky wrote:

> I'm in the process of trying to find the best OS platform on which to run
> OpenLDAP as a backend for Heimdal and Samba, as well as a replacement for
> NIS.
>
> Currently, I have a machine with a 2.8GHz Xeon and a 140G drive which 
> holds both Debian Linux (kernel 2.6.11) and Solaris 10 x86 .
>
> Here is the pertinent server info:
>
>    Linux:
>        OpenLDAP 2.3.2beta  (gcc -O2)
>        DB 4.2.52 w patches (Debian default)
>  
The DB library would be my first suspect; check and see if it has a 
dependency on -lpthread. We usually build BDB with fast gcc/asm mutexes 
but they may have built it with posixmutex support instead, which is 
significantly slower. In 4.2 the gcc mutexes are the default, but I have 
no idea how Debian configures their build.

In general, you can't construct a test like this unless you know you're 
doing apples-to-apples comparisons. If you built your own BDB library on 
Solaris x86 but used the distro's stock BDB install on Linux, you really 
have no idea if the two builds are comparable.

>    Solaris x86:
>        OpenLDAP 2.3.2beta  (SUNWspro/cc -xO4)
>        DB 4.2.52 w patches (SUNWspro/cc -xO4)
>
>
> Here's the slapd.conf I'm using:
>  
There are a lot of global directives interspersed with database-only 
directives here. Generally we discourage this because it leads to false 
assumptions about how things work. The slapd.conf(5) manpage (and 
associated config manpages) are pretty explicit about what directives 
are global vs not. In 2.3 with the LDIF configuration it will be firmly 
delineated, since directives will only be valid in specific config entries.

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