Check the logs of the apache server.

You might need to tweak the proxy_*_timeout settings in nginx , but
usually its the problem with the upstream server that is causing this.
try connecting to the upstream via http://domain:port directly and you
should face the error.



On Tue, Sep 13, 2016 at 3:22 PM, hheiko <nginx-forum@forum.nginx.org> wrote:
> I don't think there is an OS relation on the frontend, the same problem
> occurs with an Centos Nginx as Reverse proxy in front of 3 Apache backends
> on Centos - but it never occurs on windows based Apache backends...
>
> But we´re on version 1.11.4.1 Lion (http://nginx-win.ecsds.eu)
>
> Posted at Nginx Forum: https://forum.nginx.org/read.php?2,268306,269511#msg-269511
>
> _______________________________________________
> nginx mailing list
> nginx@nginx.org
> http://mailman.nginx.org/mailman/listinfo/nginx



--
Anoop P Alias

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