A couple weeks ago, Phusion Passenger (aka mod_rails) was released. I recently tested this at work, on an EC2 instance, and my initial experience was so smooth that I am already planning to use it to deploy our various Rails applications. The benchmarks I’ve seen put its performance on approximately the same level as a Mongrel cluster, but its ease of use is an order of magnitude better. All you need to do is install an Apache mod and set up a virtual host config that points to your Rails app’s public directory. You don’t even need to tell it that the directory you’re pointing to represents a Rails app – mod_rails is smart enough to figure this out by itself (although there are a few Rails specific options you can use to control the base URI or the Rails environment). No more juggling Mongrel PIDs, complicated proxy configs, or anything of that sort. Simply create a tmp/restart.txt file to have Apache reload the Rails app after you deploy a new version. Tom Copeland posted a very simple Capistrano script for mod_rails, which essentially does just that and stubs out the usual Rails Capistrano tasks that are no longer necessary in this setup.
Yesterday, DreamHost announced their support for mod_rails. I had played with Rails on DreamHost several years ago (back when FCGI was still the generally accepted way to run Rails apps), but ultimately gave up on this because of the frustrating experience (performance, stability, and ease of deployment wise). Since then, VPS hosting services (such as SliceHost) have become the prevalent solution for hosting Rails apps. But with DreamHost officially supporting mod_rails, I figured I’d give this a spin to see how well it works in practice.
I am happy to say, it seems to work just as advertised! In order to test Rails on DreamHost, I downloaded the popular Mephisto Blog Application, unzipped it into a directory on my DreamHost account, and configured the database settings (I didn’t even bother with MySQL and opted for Sqlite3 for the purpose of this test). I then went into my domain’s settings on the DreamHost Web Panel, checked the “Ruby on Rails Passenger (mod_rails)” checkbox, and pointed to my Mephisto directory’s public subdirectory as the web directory for my domain (this is important, as the web directory defaults to yourdomain.com, without the /public that mod_rails expects).
A minute or two later, my changes had been applied and I was greeted by the Mephisto blog when I hit my domain in the browser. I configured my blog’s settings and entered some dummy articles, and found the performance to be very snappy – no different from PHP apps that I am hosting at DreamHost (such as this WordPress blog).
I think this is pretty exciting. Sure, there are many other cost-effective options to deploy Rails apps these days (such as the unique and highly promising Heroku or a cheap $20 VPS slice on SliceHost), but for a personal blog or another small, reasonably low-traffic website (such as the 12 or so random Rails apps all of us are concurrently working on and too cheap to spring for VPS hosting, since most of them will never go anywhere), having the option to easily deploy these on a shared hosting account is great.
Now I am hoping that mod_rails will be extended beyond just Rails to support any Rack compliant Ruby web framework, such as Merb or Sinatra.