Re: 99.9% CPU usage still, production system

[Nick Urbanik <nicku@vtc.edu.hk>]

"Kurt D. Zeilenga" wrote:

> At 07:28 AM 2001-10-21, Nick Urbanik wrote:
> >Thank you to all the good suggestions to my previous questions.  I have
> >added ulimit -n 16000 to /etc/init.d/ldap, and have rebuilt the indexes
> >after stopping the system late at night.
>
> Note that slapd won't use more descriptors than FD_SETSIZE.
> On some systems, this can be redefined a compile time
> (-DFD_SETSIZE=16000), but on others it requires hacking
> system headers and, possibly, rebuilding the world.
>
> >However, I still have 99.9% CPU usage occasionally, and often students
> >cannot log in and get their home directories.  We are using LDAP as a
> >NIS replacement.  I am desperate, and have expended much energy in
> >this.  With linux-2.4.10-ac12 the slapd process no longer dies, but the
> >system is not available to our students at the start of each laboratory
> >session.
>
> You might ask folks on the nssldap@padl.com list for details
> on how to improve nss_ldap use of the directory.  From what I
> gather, using a caching daemon such as nscd is recommended.

Yes, we are setting that up, as well as replication.

> I note that if slapd appears to be in a tight select busy loop,
> you might experiment with usleep() within this loop.

Do you mean that it may be a good idea to patch slapd?  Okay, I'll look at
the code.

But surely we are not the only people in the world using OpenLDAP for
system authentication.   I am keen to discuss with others who are using
OpenLDAP in this way (perhaps in a university or college).

Our installation is not so huge, and the server hardware is reasonably
powerful.  The performance is totally unacceptable.  How many queries per
second are other people getting from OpenLDAP on a PC?

--
Nick Urbanik   RHCE                                  nicku@vtc.edu.hk
Dept. of Information & Communications Technology
Hong Kong Institute of Vocational Education (Tsing Yi)
Tel:   (852) 2436 8576, (852) 2436 8579          Fax: (852) 2436 8526
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