Hello! On Fri, May 12, 2017 at 01:24:14PM +0800, Wu Bingzheng wrote:
> > The last request before this 502 request is almost 20 minutes ago and its > response code is 200. > > The proxy_next_upstream conf: > proxy_next_upstream error timeout invalid_header http_502 http_503 > http_504; > > Here is the access log. The upstream server 192.168.0.6 is DOWN. The line-10 > is the 502 request: > > 1 [03/May/2017:14:35:38 -0400] "POST /x/y HTTP/1.1" 200 "192.168.0.6:8181, > 192.168.0.5:8181" 0.012 0.001, 0.011 > 2 [03/May/2017:14:35:38 -0400] "POST /x/y HTTP/1.1" 200 "192.168.0.5:8181" > 0.013 0.013 > 3 [03/May/2017:14:54:30 -0400] "POST /x/y HTTP/1.1" 200 "192.168.0.5:8181" > 0.206 0.206 > 4 [03/May/2017:15:03:08 -0400] "POST /x/y HTTP/1.1" 200 "192.168.0.5:8181" > 0.154 0.154 > 5 [03/May/2017:15:40:51 -0400] "POST /x/y HTTP/1.1" 200 "192.168.0.6:8181, > 192.168.0.5:8181" 0.012 0.000, 0.012 > 6 [03/May/2017:15:40:51 -0400] "POST /x/y HTTP/1.1" 200 "192.168.0.5:8181" > 0.014 0.014 > 7 [03/May/2017:15:40:51 -0400] "POST /x/y HTTP/1.1" 200 "192.168.0.5:8181" > 0.016 0.016 > 8 [03/May/2017:15:40:51 -0400] "POST /x/y HTTP/1.1" 200 "192.168.0.5:8181" > 0.017 0.017 > 9 [03/May/2017:15:40:51 -0400] "POST /x/y HTTP/1.1" 200 "192.168.0.5:8181" > 0.011 0.011 > 10 [03/May/2017:15:59:06 -0400] "POST /x/y HTTP/1.1" 502 "192.168.0.6:8181, > test_backend" 0.000 0.000, 0.000 > 11 [03/May/2017:15:59:07 -0400] "POST /x/y HTTP/1.1" 200 > "10.255.222.206:8181" 0.260 0.260 Looking into response status code in access logs is not enough to understand if a server is up or down. For at least the following reasons: - there might be over requests currently in flight which are not yet logged; - errors may occur while sending response body, and hence status code will not show if there was an error. It is usually a good idea to look into error logs instead. -- Maxim Dounin http://nginx.org/ _______________________________________________ nginx mailing list [email protected] http://mailman.nginx.org/mailman/listinfo/nginx
