[syslog-ng] syslog CPU usage is sawtooth
erempel at uvic.ca
Tue Nov 13 22:04:51 CET 2007
We were running syslog-ng with default setting for time_sleep (which is 0)
and were consuming approx 50% of a single CPU with syslog-ng. We were concerned about
scalability because syslog-ng is single threaded, so we started tuning with time_sleep.
We set it to 5 and adjusted related parameters (log_fetch_limit(250), log_fifo_size(1000000))
and now we are seeing a sawtooth CPU usage with a small IO wait (2%) constant on top of the
"user" cpu sawtooth.
Tooth cpu duration
1 1-10% 25 minutes
2 2-10% 10 minutes
3 3-10% 10 minutes
4 4-10% 10 minutes
This pattern repeats.
Any ideas on why the sawtooth pattern started appearing only after we adjusted these settings?
Just for the curious
Redhad 3 - build from source.
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