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Re: slapd high CPU usage

Please keep replies on the list.

On Tue, 16 Oct 2007, Angie Cao wrote:

The high CPU problem happens when log level was not turned on (means
"loglevel 0" being set in slapd.conf)

OK, so it's not (exclusively?) OpenLDAP logging that's causing your system to go slow.

Although CPU is running low right now (with slapd -d127), the message I saw is :

=> test_filter
   AND
=> test_filter_and
=> test_filter
   EQUALITY
   AND
<= test_filter 5
=> test_filter
   AND
=> test_filter_and
   AND
=> test_filter_and
=> test_filter
   EQUALITY
<= test_filter 5
<= test_filter_and 5
<= test_filter 5
bdb_search: 18222 does not match filter

are all over the place....  Wondering if this might be related with
the high CPU problem and what this indicates about. (googling around
at the moment and hopefully find the hints)

Angie


As recommended, try and find a debug level that's more appropriate -- "stats" might be good. These searches that you're concerned about will come up in a much easier to parse form:

conn=2 op=1 SRCH base="ou=Dynamic Lists,dc=example,dc=com" scope=2 deref=0 filter="(cn=dynamic list)"
conn=2 op=1 SRCH attr=*
conn=2 op=1 SEARCH RESULT tag=101 err=0 nentries=1 text=

If you find one of these that's slow (and yes, this might be as low-tech as just noting that there's a large time between debug messages being printed), then that might be a good place to start looking. This data also gives you enough that you can (more or less) replicate the search with ldapsearch(1). If you can do that yourself (instead of waiting for clients to beat slapd up) and find options that gun the CPU, you're a lot closer to fixing the issue...