Re: [RFC] Socket activation support for PHP-FPM

On Thu, Oct 18, 2012 at 2:03 PM, Reinis Rozitis <r@roze.lv> wrote: > What would be the advantage on using systemd instead of using FPMs native > 'ondemand' process manager? The ondemand process manager still keeps considerable memory allocated, and PHP-FPM currently has some idle CPU load (<1% per service, but it adds up when you manage 500+ pools on a box) when not processing requests. The ondemand process manager doesn't solve the dependency issue mentioned in the RFC (a web server requiring PHP-FPM to be ready) or allow privileges to be dropped before PHP-FPM gets invoked at all. The latter is useful for platform providers that let users configure PHP-FPM for their individual use cases but want to provide assigned "listening" sockets. Socket activation also supports replacing the entire binary (as with a PHP-FPM security update) without interrupting listening on the socket. PHP-FPM supports reloading to a limited degree, but I don't think it's possible to fully replace the executable. There is also work underway to have socket activation on the base system spawn or start full containers (like LXC) on-demand. Since PHP-FPM will, itself, be in the container, something else needs to listen on its behalf. Finally, it's a platform consistency issue. As more services move to socket activation in Fedora and Red Hat, socket units will become a sort of "common currency" for configuring which services listen where. -- David Strauss | david@davidstrauss.net