Hi! On Wed, 24 Jan 2007, Andreas Ericsson wrote: > > Activating the embedded Perl interpreter and -cache will increase > > the amount of lost memory to about 5-6M per hour. In this case, > > however, sometimes the memory usage snaps back, i.e. some of the > > lost memory is collected. I've not yet found out what triggers > > the reclaim. Still, over the course of hours, more and more > > memory is lost. Still, it's roughly linear memory loss. > > Yes. Embedded perl is known to be leaky. It's also mentioned in various > documents around the web.
Well, I think I can live without the embedded interpreter, the machine is beefy enough. > > Unfortunately, performance degradation is not just on the memory > > used front. With increased memory usage, check latency increases. > > In the worst case, this can mean that latency increases by 120s in > > about six hours. This has the net effect that for our case, we > > have to restart Nagios every two hours. > > The latency increase should only happen when the machine starts swapping. > For large networks with the access-patch thingie that could happen fairly > quickly though, I imagine. No, it's definitely not swapping (as the graphs show). My conclusions about the reasons for the degradation were drawn with exactly that in mind. > > For the case of 2.5 and 2.6 without the permissions patch, it's > > a lot less bad, but still bad enough to require restarting Nagios > > at least every eight hours. > > > > Without all the fancy stuff, we get to restarting Nagios every 24 > > hours, as described above. > > That seems a bit obsessive. Are you doing anything unusual with the system? > We have several (well over a hundred) installations where Nagios has been up > and running for several months without requiring a restart. Well, the system is a standalone Nagios server which is only that, no other services. I'll take a very close look at all the cronjobs etc. that might cause additional friction, but I doubt they're causing any trouble. > > For vanilla Nagios, at least it's clear that in whatever way > > memory is wasted, it also slows Nagios down - a possibility would > > be a linked list that is walked and gets appended over and over. > > But I guess those with knowledge of the inner workings of Nagios > > have more clue about this than I do. > > Anyone wanting to look into it should probably take a look at the > event scheduling queue. Thanks, I'll ask our resident C guru to take a close look at it. Regards, Tobias -- Never touch a burning system. ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Nagios-users mailing list Nagios-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nagios-users ::: Please include Nagios version, plugin version (-v) and OS when reporting any issue. ::: Messages without supporting info will risk being sent to /dev/null