I have a server that acts as a front-end for a cPanel mailserver in a network. The apache proxy on the front-end server ran for 152 days without fault then suddenly I now get 500/502 errors when using it to access the webmail clients of the mailserver.
The front-end server uses a signed SSL cert, the cPanel sever is using a self signed cert. Here is the error log output from the front-end server when it first started happening:
[Tue Sep 10 18:22:52.959291 2013] [proxy:error] [pid 19531] (502)Unknown error 502: [client 173.xx.xx.xx:9558] AH01084: pass request body failed to 184.xx.xx.xx:2096 (184.xx.xx.xx), referer: https://domain.com:2096/cpsess12385596/3rdparty/roundcube/?_task=mail&_refresh=1&_mbox=INBOX
[Tue Sep 10 18:22:52.959469 2013] [proxy:error] [pid 19531] [client 173.xx.xx.xx:9558] AH00898: Error during SSL Handshake with remote server returned by /cpsess12385596/3rdparty/roundcube/, referer: https://domain.com:2096/cpsess12385596/3rdparty/roundcube/?_task=mail&_refresh=1&_mbox=INBOX
The front-end server is an EC2 instance running
My VirtualHost setup for the proxy on this server is as follows:
< VirtualHost *:2096>
SSLEngine on SSLProxyEngine on SSLProxyVerify none SSLProxyCheckPeerCN off SSLCertificateFile /x/x/x/domain.com.crt SSLCertificateKeyFile /x/x/x/domain.com.key SSLCACertificateFile /x/x/x/domain.com.cabundle ProxyPass / https://184.xx.xx.xx:2096/ ProxyPassReverse / https://184.xx.xx.xx:2096/ ProxyPassReverseCookieDomain 184.xx.xx.xx:2096 domain.com ProxyPassReverseCookiePath / / SetOutputFilter INFLATE;proxy-html;DEFLATE ProxyHTMLURLMap https://184.xx.xx.xx:2096 /
As far as I can think nothing has changed on the front-end server, I didn't do an update or anything, once noticing this problem and fiddling with no success I tried a restart on both servers but it did nothing to fix this.