<div dir="ltr"><div><div><div><div>Party Line: varnish 3.x is EOL. Move to Varnish 4<br><br></div>Looks like you're logging the client side in varnishlog. Try to catch one of the Backend transactions that does this. You'll have to use varnishlog without either -c or -b or -m specified, and trawl through it manually.<br><br></div>varnishadm debug.health <br><br></div>might help as well. If all backends in a director are unhealthy, varnish will serve an immediate 503 if the request goes to that director.<br><br></div>-Jason<br></div><div class="gmail_extra"><br><div class="gmail_quote">On Wed, Oct 14, 2015 at 3:54 PM, Vlad Rusu <span dir="ltr"><<a href="mailto:vlad.rusu@cloudtroopers.ro" target="_blank">vlad.rusu@cloudtroopers.ro</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="word-wrap:break-word">Good day everyone, <div><br></div><div>I am trying to get to the bottom of the 503s sporadically logged by our Varnish servers. During monitoring, it all comes down to monitoring the state of my backends ++ varnishlog.</div><div><br></div><div>Most of the 503s come with a FetchError “backend write error: 0 (Success)” — and I can’t seem to find anything on the internet to describe what this might mean.</div><div><br></div><div>—> FetchError c backend write error: 0 (Success) <—</div><div><br></div><div>Also, none of the relevant counters in varnishstat are showing any increase (i.e. backend_unhealthy, backend_busy, backend_fail, fetch_failed..)</div><div><br></div><div>For that same request, looking at ReqEnd, it doesn’t look to me like any timeout was reached (like connect_timeout, <span style="line-height:16.8px;white-space:pre-wrap;background-color:rgb(255,255,255)">first_byte_timeout</span>, <span style="line-height:16.8px;white-space:pre-wrap;background-color:rgb(255,255,255)">between_bytes_timeout, ..</span>)</div><div><br></div><div>—> ReqEnd c 221990096 1444847550.110866785 1444847550.116131306 0.000048876 0.000905752 0.004358768 <—</div><div><br></div><div><br></div><div><b>Any chance we could get a list of possible FetchError messages and what they might mean — at least something to put us on a right track? Would surely help knowing where to start looking, especially when everything seems fine.</b></div><div><br></div><div>Also, in this FetcError scenario, <b>is it expected to see retries from Varnish?</b> If so, why would Varnish only retry some of the backends in a director and not all of them (or the .retries value)?</div><div><br></div><div><div> 44 VCL_return c hash</div><div> 44 VCL_call c pass pass</div><div> 44 Backend c 20 drpau_ssl_director drpau34ssl</div><div> 44 FetchError c backend write error: 0 (Success)</div><div> 44 Backend c 51 drpau_ssl_director drpau31ssl</div><div> 44 FetchError c backend write error: 0 (Success)</div><div> 44 VCL_call c error deliver</div><div> 44 VCL_call c deliver deliver</div><div> 44 TxProtocol c HTTP/1.1</div><div> 44 TxStatus c 503</div><div> 44 TxResponse c Service Unavailable</div></div><div><br></div><div>Should these be reflected in varnishstat’s “backend_retry”?</div><div><br></div><div>Thank you guys!</div><span class="HOEnZb"><font color="#888888"><div>Vlad Rusu</div></font></span></div><br>_______________________________________________<br>
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