> On Jan 3, 2023, at 5:17 AM, Quanah Gibson-Mount <[email protected]> wrote:
> 
> --On Friday, December 30, 2022 11:35 PM +0000 Christopher Paul 
> <[email protected]> wrote:
> 
>> Using the oldie but goodie LDAP performance testing tool, SLAMD, I've
>> been doing performance tests. What I found was that stats logging
>> (olcLogLevel: 256) degrades performance significantly. A pity, because it
>> is recommended in the manual. Also, it considered very useful by those of
>> us who've been running OpenLDAP for a while.
> 
> Yes, this is a well known, documented, and discussed issue.  It makes logical 
> sense if you think of the massive overhead incurred with logging lots of 
> information vs logging nothing at all.  I would note that the amount of perf 
> hit taken depends on the system setup.  For example, if systemd is doing 
> logging along with syslog, which is often the case these days, then that's 
> your worst case scenario, followed by just direct logging to syslog being the 
> next worst.
> 
> You might want to play with OpenLDAP 2.6 which allows direct logging to a 
> logfile on disk, completely bypassing systemd and/or syslog, this is your 
> best case scenario currently for when logging is necessary.

It gets worse on RHEL systems due to rate limiting, where large swaths of 
statements are skipped entirely.

I concur with Quanah. Use the 2.6 logger. My tests w/ a log level of sync 
(which includes stats), showed a perf boost of approximately a factor or 2.

I suppose one could achieve the same on earlier releases by disabling syslog 
and enabling the debug logger instead?

—
Shawn

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