ProxyPass and dns lookups for workers

[Robert Zimmerman <robzhttpd@xxxxxxxxx>]

Hello all,

I've got a set up that has 2.2.6 httpd servers using ProxyPass http to a tomcat complex that employs a dns rotor and vips in front of the real tomcats. So in:

ProxyPass / http://tomcatcomplex

tomcatcomplex is a rotor with multiple IPs behind it, so if and when the IP for my worker becomes unreachable, I would like for my server to perform a dns lookup and grab another IP from the dns rotor (which would have disabled the problematic IP due to failed health checks). However, there is a single dns lookup per worker, so a restart is necessary to make the httpd server stop spewing these errors:

ap_proxy_connect_backend disabling worker for (tomcatcomplex)

(110)Connection timed out: proxy: HTTP: attempt to connect to bad.ip:port (tomcatcomplex) failed

I did note the following comment in proxy_util.c:

        /*

         * Worker can have the single constant backend adress.

         * The single DNS lookup is used once per worker.

         * If dynamic change is needed then set the addr to NULL

         * inside dynamic config to force the lookup.

         */

This dynamic change seems to be what I need, however, I am clueless as to how/where to set the addr to null. Any and all help would be most appreciated!

~Bob