Florian, On Sat, Jun 12, 2010 at 9:57 AM, Florian Forster <[email protected]> wrote: > Hi Jérôme, > > On Fri, Jun 11, 2010 at 07:29:23PM +0200, Jerome Renard wrote: >> I tested the "cache_result" type, and when the DERIVE type is used, I >> do not get the correct numbers. > >> If I compare the output I get from varnishstat and the result I get >> from the rrd generated graphs the values are completely different. > > as far as I see, varnishstat divides counter values with the uptime. The > result is therefore roughly the all-time average rate of that counter. > > With collectd, you get the rate of the last $Interval seconds, for > example the last 10 seconds in the default configuration. This value may > of course be *much* smaller or larger, depending on how busy the system > was compared to the average usage. > >> I guess this is due to de derive type. > > "COUNTER" and "DERIVE" only differ in the overflow and counter-reset > cases. Since overflows are next to impossible with 64bit counters, and > because the counters are reset to zero when varnish is restarted, I > opted for optimizing for the latter case, i.e. used "DERIVE".
Yeah, I figured that out a bit earlier today. Actually we were serving a different purpose, I wanted to fetch the exact numbers returned by varnishstat and get them displaied by RRDTool and I completely overlook the time interval part (like monitoring every 10 seconds) :/ So know everything is crystal clear and we are on the same page :) > > You can find a more in-depth explanation of the difference between > "COUNTER" and "DERIVE" in the collectd wiki at [0]. > >> But the problem is that I never get any value, it is always set to >> zero, here is what I get from the debug: > > Is the counter value actually increasing? Otherwise a rate of (close to) > zero is expected and normal. Yes, that is what I found by looking in uc_update() I'll fix my stuff :) Thanks for your feedback. Best Regards -- Jérôme :) _______________________________________________ collectd mailing list [email protected] http://mailman.verplant.org/listinfo/collectd
