503 Error, first byte timeout. Which Backend?

[Stephen Wood]

Grepping won't really do it for you. You can use varnishlog to capture just
503 status codes by doing the following:

varnishlog -m TxStatus:503

Leave that running and once you get a full output go ahead and paste it
here and we'll take a look at it (remember to scrub any sensitive
information).


On Thu, Jan 16, 2014 at 5:21 PM, Jason Price <japrice at gmail.com> wrote:

> I was doing that... Grep -B 1... But the thread index number (left most
> number) is different... Or is that different because it's doing back end
> processing?
>
> Jason <-- still figuring out varnishlog
> On Jan 16, 2014 7:39 PM, "Stephen Wood" <smwood4 at gmail.com> wrote:
>
>> You should see this value as "Backend" in your varnishlog output. It
>> should be right above the FetchError line you posted.
>>
>>
>> On Thu, Jan 16, 2014 at 3:38 PM, Jason Price <japrice at gmail.com> wrote:
>>
>>> So, I have backends which are occasionally slow.  So varnish responds
>>> with a 503 error.
>>>
>>> How can I determine WHICH backend was used, which failed to respond in a
>>> timely manner?
>>>
>>> In varnishlog, I see errors like the following:
>>>
>>>   180 FetchError   c http first read error: -1 11 (Resource temporarily
>>> unavailable)
>>>
>>> Reading the code, the -1 SEEMS to indicate that the backend closed the
>>> connection on this error.  vcl_error doesn't give me access to beresp
>>> variables (like beresp.backend.name or IP, which would answer the
>>> question).  This indicates that obj.* does NOT include a backend
>>> indication...<https://www.varnish-cache.org/docs/3.0/reference/vcl.html#variables>
>>>
>>> Any way I can figure out which backend is failing me?
>>>
>>> --Jason
>>>
>>> _______________________________________________
>>> varnish-misc mailing list
>>> varnish-misc at varnish-cache.org
>>> https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc
>>>
>>
>>
>>
>> --
>> Stephen Wood
>> www.heystephenwood.com
>>
>


-- 
Stephen Wood
www.heystephenwood.com
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