Phusion Passenger users guide

これか？ PassengerMinInstances

It is very hard to obtain a full list of web applications defined in the Apache configuration file(s). In other words, it’s hard for Phusion Passenger to know which web applications are deployed on Apache until a web application is first accessed, and without such a list Phusion Passenger wouldn’t know which web applications to pre-start. It’s probably not completely impossible to obtain such a list, but this brings us to the following point; Users expect things like mod_env to work even in combination with Phusion Passenger. For example some people put “SetEnv PATH=….” in their virtual host block and they expect the web application to pick that environment variable up when it’s started. Information like this is stored in module-specific locations that Phusion Passenger cannot access directly. Even if the previous bullet point is solved and we can obtain a list of web appl...

Full article: http://www.modrails.com/documentation/Users%20guide%20Apa...