Varnish unresponsive on our server

[Guillaume Quintard]

Hi Uday,

pz_list and recv_queue are not (to my knowledge) Varnish counters, where
are you seeing them?

I doubt Varnish is actually replying with 0, so that probably is your
client faking a response code to have something to show. But that's a
detail, as the unresponsiveness is real.

Could you share a "varnishstat -1" of the impacted machine?

-- 
Guillaume Quintard


On Thu, Jun 20, 2024 at 9:30 AM Uday Kumar <uday.polu at indiamart.com> wrote:

> Hello all,
>
> We are facing frequent issues of varnish unresponsiveness for sometime on
> our production server.
>
> During this time we have seen that pz_list is being increased to ~3000 and
> recv_queue is increased to ~130
> Also, varnish is responding with response code '0' for sometime, which
> meant unresponsive.
>
> This is causing multiple 5xx on front ends.
>
> FYR:
> User request count during this time is normal.
>
> Note:
> During this time, we have confirmed that our backend servers are healthy
> without any issues.
>
>
> May I know what could be the reason for this behaviour at varnish?
>
> Please give me the direction on how to debug this issue.
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> varnish-misc mailing list
> varnish-misc at varnish-cache.org
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>
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