[users@httpd] ProxyPass and dns lookups for workers

[Robert Zimmerman <ro...@gmail.com>]

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