increase the min thread per pool ( 100 or more) idle thread cost nothing , spawning a new thread lasts...
Simon Males napsal(a): > On Fri, Jul 15, 2011 at 11:15 AM, Simon Males <[email protected]> wrote: >>> The Varnish munin plugins have alerted me a number of times (say less >>> then 5) that N dropped work requests (n_wrk_drop) is greater then 1. >>> >>> According to Kristian Lyngstol's post [1] this is represents when the >>> request queue it full. Additionally I believe the overflowed work >>> requests (n_wrk_overflow) will always be greater then n_wrk_drop. >>> >>> I think I should be trying to tackle two issues: Limit requests >>> overflowing, followed by increasing the size of the request queue. >>> >>> Of the below startup parameters I believe thread_pools should match >>> the number of cores the server has and increase the maximum number of >>> threads to possibly double (from 25 to 50?). >>> >>> DAEMON_OPTS="-a :80 \ >>> -T localhost:6082 \ >>> -f /etc/varnish/default.vcl \ >>> -S /etc/varnish/secret \ >>> -w 10,25,120 \ >>> -p listen_depth=8192 \ >>> -p log_hashstring=off \ >>> -p lru_interval=60 \ >>> -p sess_timeout=10 \ >>> -p shm_workspace=32768 \ >>> -p ping_interval=1 \ >>> -p thread_pools=4 \ >>> -s malloc,2G" >> As overflow_max is default set to 100%, I believe I essentially need >> to increase the number of worker threads to increase the ratio. To >> increase the threads, I'll increase the thread_pools. > > Since this post, I increased the thread_pools to 8, though today I've > had another spurt of dropped work requests. It's definitely related to > a sudden rise of traffic, as the dropped requests happen moment after > sending an E-Mail to our users. > > The servers have 16 cores, so I've increased the thread_pools to 16 > now. With 10 minimum threads per pool, I now have 160 threads waiting > to serve. > > Hopefully this will minimise the chance of dropping work requests. > _______________________________________________ varnish-misc mailing list [email protected] https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc
