Updating phusion passenger
The only change I did need to make to my redmine installation was a small adaptation of public/.htaccess: I moved all Rewrite directives into an block as Phusion Passenger deactivates mod_rewrite in it's standard configuration because of some compatibility problems.
If there are no good reason against running Redmine using Phusion Passenger I would like to see it mentioned in the Wiki as an alerternative to mongrel_cluster.
The setup that we currently recommend is to combine Phusion Passenger for Apache or Phusion Passenger for Nginx, with Phusion Passenger Standalone.
One must first identify the Ruby version that you use most.
Unix domain sockets are significantly faster than TCP sockets.
The ODD part: If a route defined in the Sinatra controller is requested (i.e: https://myapp.ch/infos), passenger is started and the requested page is served as expected.
It comes with many features that makes your life easier and your application perform better.