Ruby on Rails® for Microsoft Developers

11.2. Performance and Optimization

An important step before releasing your application to the world is to ensure that the application's performances are acceptable. This section briefly provides pointers to do just that.

11.2.1. Measuring Performance

Because it is said that premature optimization is the root of all evils, you first must determine how well your application performs and identify where possible bottlenecks exist. In other words, you need to be able to benchmark and profile your application.

Several tools are available to measure the performance of your applications. The first most obvious approach is to check your production logs.

Remember, applications running in development mode are usually much slower than in production mode. You can run ruby script/server -e production or uncomment ENV['RAILS_ENV'] ||= 'production' in your config\environment.rb file, to ensure that the application will run in production mode.

11.2.1.1. Reading Logs

Each entry within the logs provides timing information. Prior to Rails 2.2, the logs would report the throughput for the request (the number of requests per seconds as shown here):

Processing ArticlesController#index (for 127.0.0.1 at 2009-01-04 03:49:51) [GET] Session ID: f88e2cf214faf1ad32c8c3564900828a Parameters: {"action"=>"index", "controller"=>"articles"} Rendering template within layouts/articles Rendering articles/index Completed in 0.01900 (52 reqs/sec) | Rendering: 0.00800 (42%) | DB: 0.00100 (5%) | 200 OK [http://localhost/] ...