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<p class="MsoNormal">Hello,<o:p></o:p></p>
<p class="MsoNormal">I am totally new to nginx, so please forgive me if I am wrong.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I propose the following change:<o:p></o:p></p>
<p class="MsoNormal"><a href="https://github.com/nginx/nginx/blob/master/src/http/ngx_http_upstream_round_robin.c#L615">https://github.com/nginx/nginx/blob/master/src/http/ngx_http_upstream_round_robin.c#L615</a><o:p></o:p></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">From: <span class="pl-k">if</span> (state & NGX_PEER_FAILED)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">To: <span class="pl-k">
if</span> (state & (NGX_PEER_FAILED || NGX_PEER_NEXT))<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""><o:p> </o:p></span></p>
<p class="MsoNormal">Note: The value causing us trouble:<o:p></o:p></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">state = NGX_PEER_NEXT // on HTTP 404
<o:p></o:p></span></p>
<p class="MsoNormal">Comes from: <a href="https://github.com/nginx/nginx/blob/master/src/http/ngx_http_upstream.c#L4097">
https://github.com/nginx/nginx/blob/master/src/http/ngx_http_upstream.c#L4097</a><o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Regular round robin seems to work fine. But with a configuration like:<o:p></o:p></p>
<p class="MsoNormal"><b><span style="font-family:"Courier New"">upstream live {<o:p></o:p></span></b></p>
<p class="MsoNormal"><b><span style="font-family:"Courier New""> server 10.16.48.227:8090;<o:p></o:p></span></b></p>
<p class="MsoNormal"><b><span style="font-family:"Courier New""> server 10.16.48.228:8090 backup;<o:p></o:p></span></b></p>
<p class="MsoNormal"><b><span style="font-family:"Courier New"">}<o:p></o:p></span></b></p>
<p class="MsoNormal"><b><span style="font-family:"Courier New""><o:p> </o:p></span></b></p>
<p class="MsoNormal">We get a nice failover for HTTP 502. But for HTTP 404 we get a forever-loop, just like the one mentioned in
<o:p></o:p></p>
<p class="MsoNormal">Changes with nginx 1.3.0:<o:p></o:p></p>
<p class="MsoNormal"> *) Bugfix: nginx might loop infinitely over backends if the<o:p></o:p></p>
<p class="MsoNormal"> "proxy_next_upstream" directive with the "http_404" parameter was<o:p></o:p></p>
<p class="MsoNormal"> used and there were backup servers specified in an upstream block.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">So we get looping despite the fix. The proposed edit stops the looping for us, but I cannot see the full consequences. And of course it is possible that we can fix it by just some configuration change.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">What do you think?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks<o:p></o:p></p>
<p class="MsoNormal">Adam<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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