Threads + thread queue length
viktor.villafuerte at optusnet.com.au
Mon Oct 12 06:17:05 CEST 2015
Hi all you carpenters and other Varnish using folk,
There are couple of things in the output of varnishstat that puzzle me a
MAIN.sess_drop 0 0.00 Sessions dropped
MAIN.sess_dropped 3809332 0.32 Sessions dropped for
MAIN.fetch_no_thread 58746 0.01 Fetch failed (no
MAIN.pools 2 . Number of thread pools
MAIN.threads 1255 . Total number of
I've got 2 pools of 4000 threads set in Varnish config and
man varnish-counters says:
Count of sessions silently dropped due to lack of worker thread.
Number of times session was dropped because the queue were too long
already. See also parameter queue_max.
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
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
Could anybody shed bit of light on this for me?
Optus Internet Engineering
t: +61 2 80825265
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