Varnish sometimes delays requests for minutes

[Tollef Fog Heen]

> The hung requests only happen on pages that have expired caches, but not every
> request to that page while it is expired will trigger a hang.  That is, I have
> a difficult time reproducing it, and kinda have to just watch requests in the
> corner of my eye while going about other duties.
> 
> I am fairly certain that these hangs are not the fault of the backend, but not
> completely sure - mark me down at 95% certainty.

My bet would be on the backend, but it's hard to tell without
varnishlog.

Something like varnishlog -m 'ReqEnd:([\d.]+\s){4}\d{2,}\.' will get you
just requests that take more than 10s to complete, which should
hopefully be easier to read than the all the raw requests.

If you have trouble deciphering a varnishlog record, please post it here
and we can try to help you.

Cheers,
-- 
Tollef Fog Heen
Technical lead, Varnish Software
t: +47 21 98 92 64