Mad Marmot

Switching from mongrel to mod_rails.

Posted by Luke Ludwig Sun, 13 Apr 2008 14:40:00 GMT

A mod_rails for Apache, also called Phusion Passenger, has been released.  I switched this blogs deployment from using mongrel to using mod_rails in less than 20 minutes without any problems. The installation procedure is dead simple. I had to look up one thing in the user's guide, how to serve the rails app off a sub path of the domain (lukeludwig.com/blog), and I found it quickly. Overall I am extremely impressed and am curious how Passenger will do with higher traffic production sites.

Previously I was running this blog on a single mongrel instance, which is all that is needed due to the low traffic on this site. But lets just say that I wrote an article with great content and it got digged, causing traffic to spike like crazy for a few days. The single mongrel would quickly be overwhelmed and my site would be for the most part, unusuable, until I noticed and was able to start up a whole mongrel cluster of say a dozen mongrels. My server has 1 GB of RAM, most of which goes unused. Passenger is able to handle the number of rails instances in a much nicer manner. From a configuration perspective, I set the RailsMaxPoolSize to 12 and I'm done. Passenger will run as many rails instances as it needs depending on load, up to the max of 12. When traffic slows down, it kills the idle rails instances to conserve memory. Great stuff.