502 & 504 error, again

[Stefan Caunter]

On Sun, Jan 1, 2012 at 11:37 PM, Geoge.Q <quan.nexthop at gmail.com> wrote:
> I know it should be a well-known issue.
> I searched and try to find out what on earth it is, but I failed.
>
> Step:
> 1) nginx works as reverse proxy and the version is V1.0.5,
>    OS: Debian 5.0.3, Kernel Version 2.6.32
>
> 2) Enabled http 1.1,   504 error  is popup in client;

You enabled the HTTP/1.1 protocol? Where? What were you doing before?

> the error log indicates:
> -------------------------------------------------
> 2011/12/30 09:40:06 [error] 11013#0: *1 upstream timed out (110: Connection
> timed out) while reading response header from upstream, client:
> 10.208.127.142, server: 1.1.1.1, request: "POST
> /QueryStatManage/StatStudentAction.aspx HTTP/1.1", upstream:
> "http://1.1.1.1:80/QueryStatManage/StatStudentAction.aspx", host: "1.1.1.1",
> referrer: "http://1.1.1.1/QueryStatManage/StatStudentAction.aspx"
> -------------------------------------------------
>

How large is the POST?

>
> 3) increase the vaule
>      > proxy_read_timeout 600s
>      > proxy_send_timeout 600s
>
>    this time, it is poped up 502, the error logs indicates
> ------------------------------------
> 2011/12/30 09:53:54 [error] 11173#0: *1 upstream prematurely closed
> connection while reading response header from upstream, client:
> 10.208.127.142, server: 1.1.1.1, request: "POST
> /QueryStatManage/StatStudentAction.aspx HTTP/1.1", upstream:
> "http://1.1.1.1:80/QueryStatManage/StatStudentAction.aspx", host: "1.1.1.1",
> referrer: "http://1.1.1.1/QueryStatManage/StatStudentAction.aspx"
>

Does the back end application work without nginx as proxy? What is the
nginx configuration? We need details to help you.

> 4) Someone told me that there is a kernel bug in linux, I am not sure, can
> someone see the same issue ?

Irrelevant. These are HTTP errors, with HTTP logging. If you have
kernel errors, send your logs to the appropriate maintainers :)

You are running an ASP.NET application. You have to correctly set
proxy timeouts and buffer sizes to proxy to ASP applications, assuming
the application works.


Stefan Caunter
http://scaleengine.com/contact