Hi Andreas, On Thu 12 Nov 2015 13:55:01, Viktor Villafuerte wrote: > >From Varnish source code: > > PARAM( > /* name */ thread_pool_add_delay, > /* tweak */ tweak_timeout, > /* var */ thread_pool_add_delay, > /* min */ 0.000, > /* max */ none, > /* default */ 0.000, > /* units */ seconds, > /* flags */ 0| EXPERIMENTAL, > /* s-text */ > "Wait at least this long after creating a thread.\n" > "\n" > "Some (buggy) systems may need a short (sub-second) delay between " > "creating threads.\n" > "Set this to a few milliseconds if you see the 'threads_failed' " > "counter grow too much.\n" > "Setting this too high results in insuffient worker threads.\n", > /* l-text */ "", > /* func */ NULL > ) > > which would make the value SECONDS > > BUT > > >From Varnish docs: > > -p thread_pool_add_delay=2 (default: 20ms, default in master: 2ms) > Reducing the add_delay lets you create threads faster which is essential > - specially at startup - to avoid filling up the queue and dropping > requests. >
The above section is taken from Varnish website. I guess it does not actually say that the unit value is seconds or milliseconds but I do find this confusing as it strongly (IMHO) suggests that the value is milliseconds. Also possibly there are other better resources on the web that state this clearly and I didn't find.. could be my bad v > > > v > > > > > On Thu 12 Nov 2015 12:40:27, Viktor Villafuerte wrote: > > I think I might have found the problem here.. :/ > > > > thread_pool_add_delay > > > > the doco says that the values are in milliseconds but if I set this to 2 > > (which should be 2ms) it makes the server handle traffic very badly and > > only very gradually increases perfomance.. However if I set this to 0 > > then everything runs immediately and well. Furthermore in the docs it > > says: > > > > Reducing the add_delay lets you create threads faster which is > > essential - specially at startup - to avoid filling up the queue and > > dropping requests. > > > > which would exactly fit my (sad) scenario below.. > > > > > > Could anybody confirm that the value is in milliseconds and not in > > seconds? > > > > thanks > > > > v > > > > > > > > On Wed 11 Nov 2015 09:52:52, Viktor Villafuerte wrote: > > > I'm bumping this 'thread' up to the top since CJ Ess has just asked a > > > question related to threads also.. I hate doing this but I'm hoping that > > > somebody could (maybe) answer this too..? > > > > > > v > > > > > > On Mon 12 Oct 2015 15:17:05, Viktor Villafuerte wrote: > > > > Hi all you carpenters and other Varnish using folk, > > > > > > > > There are couple of things in the output of varnishstat that puzzle me a > > > > little.. > > > > > > > > MAIN.sess_drop 0 0.00 Sessions dropped > > > > MAIN.sess_dropped 3809332 0.32 Sessions dropped for > > > > thread > > > > MAIN.fetch_no_thread 58746 0.01 Fetch failed (no > > > > thread) > > > > MAIN.pools 2 . Number of thread pools > > > > MAIN.threads 1255 . Total number of > > > > threads > > > > > > > > I've got 2 pools of 4000 threads set in Varnish config and > > > > man varnish-counters says: > > > > > > > > sess_drop > > > > Count of sessions silently dropped due to lack of worker thread. > > > > > > > > sess_dropped > > > > Number of times session was dropped because the queue were too long > > > > already. See also parameter queue_max. > > > > > > > > fetch_no_thread > > > > beresp fetch failed, no thread available > > > > > > > > > > > > This tells me that there's no lack of worker threads (good!), but the > > > > thread queue length does get too long and subsequently sessions get > > > > dropped (bad!). Also backend fetch failed due to no threads being > > > > available (what?) > > > > > > > > > > > > Now the puzzling bit :) > > > > > > > > 1) why would the thread queue get too long if there seems to be NO lack > > > > of threads to use? > > > > > > > > 2) why would there be no threads if there seems to be NO lack of threads > > > > > > > > 3) 'See also the parameter queue_max' - but I cannot find any mention of > > > > such parameter anywhere around? Where does this ellusive paramater live > > > > then? > > > > > > > > > > > > Could anybody shed bit of light on this for me? > > > > > > > > > > > > > > > > > > > > -- > > > > Regards > > > > > > > > Viktor Villafuerte > > > > Optus Internet Engineering > > > > t: +61 2 80825265 > > > > > > > > _______________________________________________ > > > > varnish-misc mailing list > > > > [email protected] > > > > https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc > > > > > > -- > > > Regards > > > > > > Viktor Villafuerte > > > Optus Internet Engineering > > > t: +61 2 80825265 > > > > > > _______________________________________________ > > > varnish-misc mailing list > > > [email protected] > > > https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc > > > > -- > > Regards > > > > Viktor Villafuerte > > Optus Internet Engineering > > t: +61 2 80825265 > > > > _______________________________________________ > > varnish-misc mailing list > > [email protected] > > https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc > > -- > Regards > > Viktor Villafuerte > Optus Internet Engineering > t: +61 2 80825265 > > _______________________________________________ > varnish-misc mailing list > [email protected] > https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc -- Regards Viktor Villafuerte Optus Internet Engineering t: +61 2 80825265 _______________________________________________ varnish-misc mailing list [email protected] https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc
