Is it correct that there are particular times when you may need to restart Webrick to see your changes?

Question

I heard Kevin Skoglund (lynda.com) say that it is good practice to get in the habit of restarting Webrick frequently during development. Although generally you do not need to restart Webrick to see your changes, he implied that there are particular times when this may be needed? Does anyone know what those circumstances might be? This made wonder if Webrick is kind of flaky.

Answer 1

You'll need to restart if you change your database schema, or if you add/change a constant.

I think Rails uses Mongrel by default for development now, but those still apply.

Answer 2

If you are working through the Lynda.com tutorials, then you are working with a much earlier version of Rails then the most recent release (2.3.2).

The short answer is, large amounts of restarts are no longer necessary when working in the development environment. I think Kevin has you restart the server every time you change a Model object, but that isn't the case anymore.

The general rule of thumb is: restart every time you change something in the config or lib folder . . . any other code changes shouldn't necessitate a restart. It is also a good idea to restart when you change your routes.rb file as well, although when working with it today I noticed it is not a hard and fast rule.

The reason for all of the server restarts isn't necessarily because your webserver (webrick, mongrel, phusion passenger) is flaky, but because when your Rails app has started up, there are certain things loaded into memory, load paths, initializers, environment data. When you make a change to one of these files, you want to restart your application so that the changes take place (as opposed to the old stuff that is still running in memory)