Hi Joe, 2017-03-30 21:33 GMT+02:00 Joe Muller <jmul...@arccorp.com>:
> We are running Apache 2.4.18 with mod_proxy and recently moved a backend > site from a Weblogic server to an IIS server, and now we are facing > intermittent issues when users connect. Users tend to receive the error: > > > Proxy Error > The proxy server received an invalid response from an upstream server. > The server could not handle the request GET/. > Reason: Error reading from remote server. > > > The logs usually look something like this: > > [Wed Mar 29 14:10:42.893220 2017] [proxy:error] [pid 26435:tid > 139648193414912] [client 12.34.56.78:62044] AH00898: Error reading from > remote server returned by / > > or this: > > [Wed Mar 29 14:14:17.085777 2017] [proxy_http:error] [pid 26519:tid > 139648184960768] (104)Connection reset by peer: [client 11.22.33.44:60271] > AH01102: error reading status line from remote server > iisserver.internaldomain.com:70, referer: http://externaldomain.com/? > reqp=1&r > eqr= > > > Below is the current config (IP addresses have been changed to protect the > innocent.) We have tried several different options but had no luck. > Anybody else ever experience this ? We would appreciate any and all help > on the matter. We do not see any errors on the backend IIS server when > this occurs. I have yet to do a network trace between the systems. > > -Joe > > <VirtualHost a.b.c.d:80> > ServerName www.externaldomain.com > ServerAlias externaldomain.com > SSLEngine off > TransferLog "logs/www_externaldomain_access_log" > ErrorLog "logs/www_externaldomain_error_log" > > <Location /> > ProxyPass http://iisserver.internaldomain.com:70/ > ProxyPassReverse http://iisserver.internaldomain.com:70/ > SetEnv force-proxy-request-1.0 1 > SetEnv proxy-nokeepalive 1 > </Location> > </VirtualHost> > The error seems related to the IIS server either dropping the connection with httpd or returning something malformed response. Have you tried to make the same request directly to the IIS server and see what happens? Moreover, I would do the following: 1) increase the https://httpd.apache.org/docs/2.4/mod/core.html#loglevel and see if anything comes up. 2) https://httpd.apache.org/docs/2.4/mod/mod_dumpio.html may help in debugging the issue, even if I am not 100% sure (never tried) if it works with mod_proxy too. Hope it helps! Luca
