Mongrel process title GemPlugin

This is a simple plugin for Mongrel which changes the process title to reflect what it's currently doing. You can then determine a given Mongrel server's status using “ps”.

For example:

mongrel_rails [10010/2/358]: handling 127.0.0.1: HEAD /feed/cal/global/91/6de4, GET /feed/index
               |     | |     |        |          |
               |     | |     |        |          The current req (method / path)
               |     | |     |        |
               |     | |     |        The client IP
               |     | |     |
               |     | |     What it's doing
               |     | |     
               |     | Requests processed during server lifetime
               |     |
               |     Requests currently queued/being processed concurrently
               |
               The port that Mongrel is serving

This is almost entirely based on Alexander Staubo's Rails plugin with the same name:

purefiction.net/mongrel_proctitle/

The main difference is that the GemPlugin will automatically be loaded by all mongrels without additional code changes or configuration.

Monitoring Mongrels


Once the program is installed, you should be able to see the formatted process title by running:

$ ps -axwwo pid,command | grep mongrel_rails

See ps(1) for more options. You may want to include %cpu, rsz, %mem, or other fields in output.

There's also a `mongrel_top` executable included in the gem that works like top(1) but displays only mongrel processes:

$ mongrel_top

By default, `mongrel_top` updates the display every 0.25 seconds and shows the pid and process title. You can select a different interval and fields with the -s and -o arguments, respectively:

$ mongrel_top -s 0.1 -o pid,%cpu,rsz,command

The “command” field must be included.

Installation


This version of the plugin is packaged specifically as a Mongrel GemPlugin. Install using:

gem install mongrel_proctitle --source=http://tomayko.com

Once installed, all new mongrels will automatically load the plugin during startup. If you would prefer to control which mongrels load the plugin, do not install this gem. Use the directions below instead.

Installing into a specific Rails app only


See Alexander Staubo's original project:

purefiction.net/mongrel_proctitle/

Showing your application-specific revision/release in the title


In your application's start-up process, re-open Mongrel::Proctitler and define a get_app_revision method. In a Rails app, a good place to do this is in RAILS_ROOT/config/environments/production.rb. An example get_app_revision method might look like:

def get_app_revision
  `cat ./REVISION`.chomp
end

License


I've included the LICENSE file from the original mongrel_proctitle distribution. It is the “New and Simplified BSD License”. More information on this license can be found at:

www.opensource.org/licenses/bsd-license.php