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Re: Problem with 2.0.7: cpu usage

Pedro Melo wrote:

> Hi,
> i'm using 2.0.7 with qmail-ldap. The ldap server contains around 270k
> entries.
> We are getting 1 query/sec avg, but we have peek's of 30 or more per sec.
> Performance is ok, and everything works like a charm most of the time,
> but from time to time, slapd start's to eat all the CPU, and stop's
> anwsering queries. Load's shoot up to 32 (strangly, is always the same
> load avg...)
> Another thing that happens ist that I start loosing entries, but I
> suppose that's because I have no other choice than to killall -9 slapd
> and restart it...
> Is there a "debug guide", hints on where to look for what's going on?

I experienced something similar in the past; I saw postings that hinted
to tcp wrappers and rlookups as possible causes; not directly themselves,
but their frequent resorting to dns calls, possibly combined with dns
malfunctions. As a matter of fact, I noted a reduction of such occurrences
when compiling without tcp wrappers and when using IPs instead of host
names for very demanding clients (web/proxy/imap auth, sendmail, and so).


Dr. Pierangelo Masarati               | voice: +39 02 2399 8365
Dip. Ing. Aerospaziale                | fax:   +39 02 2399 8334
Politecnico di Milano                 | mailto:masarati@aero.polimi.it
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