Apache PHP-FPM unix domain sockets questions

["Rose, John B" <jbrose@xxxxxxx>]

After looking at the documentation on httpd.apache.org and wiki.apache.org I have a few questions ...

1. I have seen examples of both "ProxyPassMatch" and "SetHandler" used to implement Unix Domain Sockets. Which is better?

       2. On the wiki page it says "Using too many sockets will cause apache to give a (99)Cannot assign requested address: error" 

          If PHP-FPM is configured to use "ondemand" does this help avoid that problem?

      3. If "ondemand" is used in PHP-FPM, is it still advisable to tweak /proc/sys/net/ipv4/tcp_tw_reuse?

      4. What are some advisable ways to determine an ideal value for "ulimit" if using Unix Domain Sockets?

       

Thanks