Hi Max. I´ve tried the parameters below: - host_inter_check_delay_method=n - service_inter_check_delay_method=n - sleep_time=0.02 Result: no difference. Thanks. <div class="gmail_quote">On Tue, Aug 23, 2011 at 8:06 PM, Max Schubert <<a href="mailto:maxs@webwizarddesign.com">maxs@webwizarddesign.com</a>> wrote: <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div class="im">On Tue, Aug 23, 2011 at 5:48 PM, Mark Goldfinch <<a href="mailto:mark.goldfinch@modicagroup.com">mark.goldfinch@modicagroup.com</a>> wrote: > On this particular point, the overall system CPU statistics displayed at the top of "top" are an average across all CPUs. As previously mooted, Nagios core isn't multi-threaded, so it can only max a single core. 100% of 1/8 CPUs == 12.5% hence why you're seeing 87.5% idle time, 7 of your cores are not stressed out. </div>Nagios forks a new process to execute each check - so it will take advantage of multiple cores as long as the kernel scheduler is working properly :p - on our biggest pollers we get 300-400 checks running at a time in parallel at any given time during the polling cycle. Some blog posts I wrote about Nagios performance that might help (some of the topics have been covered): <a href="http://www.semintelligent.com/blog/?q=Performance" target="_blank">http://www.semintelligent.com/blog/?q=Performance</a> We found that changing host and service inter-check delay to 'n' for no delay made a big difference - also, changing sleep time to 0.02 and compiling Nagios with nanosleep enabled helps a lot as well - and we added a few additional patches to remove hard-coded sleep statements that were in the code that were causing Nagios to sleep more than we wanted. Right now on an HP DL385 we max out at about 10k checks (combo of host and service checks) per 5 minutes with a sustained service check latency of 2-3 seconds - that is a quad core host with 8 GB of RAM. We have latency requirements that are very specific to our environment - we keep all pollers at less than 10 secs service latency at all times. - Max <div><div></div><div class="h5"> ------------------------------------------------------------------------------ EMC VNX: the world's simplest storage, starting under $10K The only unified storage solution that offers unified management Up to 160% more powerful than alternatives and 25% more efficient. Guaranteed. <a href="http://p.sf.net/sfu/emc-vnx-dev2dev" target="_blank">http://p.sf.net/sfu/emc-vnx-dev2dev</a> _______________________________________________ Nagios-devel mailing list <a href="mailto:Nagios-devel@lists.sourceforge.net">Nagios-devel@lists.sourceforge.net</a> <a href="https://lists.sourceforge.net/lists/listinfo/nagios-devel" target="_blank">https://lists.sourceforge.net/lists/listinfo/nagios-devel</a> </div></div></blockquote></div>