何故Railsはmod_ruby上での運用例が少ないのですか？

“mod_ruby uses a shared interpreter per Apache process, which means that multiple Rails applications on the same Apache setup with mod_ruby would share the framework classes. This doesn't work well with the Rails model of using class-level configuration attributes, so it’s considered unsafe to use mod_ruby and Rails with more than one application running per Apache setup, because different applications may start sharing the classes.

” Rubyインタプリタを共有するのでApache上でRailsアプリを複数稼動させられないですね。 速度的にはどうなんでしょう。

Passenger