[Varnish] #188: thread pileup
Varnish
varnish-bugs at projects.linpro.no
Tue Dec 11 12:24:50 CET 2007
#188: thread pileup
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Reporter: steinove | Owner: phk
Type: defect | Status: new
Priority: high | Milestone:
Component: varnishd | Version: 1.1.1
Severity: normal | Resolution:
Keywords: |
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Changes (by phk):
* owner: des => phk
* component: build => varnishd
Comment:
My best diagnosis, is that the backend is very slow for some particular
popular object.
One thread picks it up from the backend and a LOT of requests gets parked
on the busy object until it comes back from the backend.
Once it comes back, all the parked requests gets reinjected and causes the
thread explosion.
Some kind of pacing algorithm is obviously called for, the trick is to
find one that doesn't need too many carefully tweaked numbers to work
generally and reliably.
Thinking...
/phk
--
Ticket URL: <http://varnish.projects.linpro.no/ticket/188#comment:1>
Varnish <http://varnish.projects.linpro.no/>
The Varnish HTTP Accelerator
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