Tuesday, April 19, 2005

Benchmarking OS performance with Open LDAP

Came across this very interesting discussion,


In the process of trying to find the best OS platform on which to runOpenLDAP as a backend for Heimdal and Samba, as well as a replacement forNIS;
results given;

A run of the 10 ldapsearch requests at a time yield the following (20 server threads): Linux : 10 ldapsearches on (objectClass=*) : ~3:15 Sol10x86 : 10 ldapsearches on (objectClass=*) : ~0:06.5So the queries that take over 3 minutes on Linux take less that 7 secondson Solaris x86.

this is really unique,
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.
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.


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