On Wed, 2001-09-26 at 14:36, Russell P. Sutherland wrote:
> Does anyone have any experience with performance
> numbers with the following vauth modules:
>
> mySQL
> LDAP
> CDB
>
> Given a NFS mounted Maildir area, at what user populations
> does mySQL or LDAP "win" over CDB. It seems to me that
> CDB is the "simplest" way to perform vpopuser authentication.
What I've seen is cdb compilation starts taking "too long"
somewhere above 5,000 users. cdb needs to be recompiled
when ever a user is added/deleted/modified.
cdb also has possible file locking problems when multiple
updates are happening to the password file. It depends on
how your NFS server handles file locking. Some NFS servers
are totally broken, and I've seen vpasswd files corruppted
because of it.
mysql does not have the compilation delay or the file
locking problem. I've seen it scale very well above
300,000 users. MySQL also supports replication, so
you can build a clustered system.
Personally, I think LDAP should be taken out and shot,
then beaten mercelessly and... etc, etc.
I bet the people who came up with XML and WAP also
came up with LDAP. Have you ever looked at the
function calls to access an LDAP server. Horribly
in-efficent. I've seen many an LDAP server break under
the high transaction loads of a busy mail server.
LDAP seems to be fine for departmental stuff, and
should stay there (and hopefully die).
Ken Jones
"the opinions expressed herein are right and you are wrong:)"
