Rails%203%20In%20Action

Rate limiting
fine for a project with a small amount of tickets, but if a project grew to something say,
the size of the Rails project, 14 then it would be problematic because Rails would have
to instantiate thousands of new Ticket objects per-request. That’s no good.
Now that you’re versed in the Ways of the API, you can tackle potential problems
with it. One of the potential problems with this API is that you’ll have too many users
accessing it all at once, which may cause performance problems with the application.
To prevent this, you’ll implement the rate of requests people can make to your server.
13.3 Rate limiting
When a server receives too many requests, it can seem unresponsive. This is simply
because it is too busy serving existing requests to serve the hoard of incoming
requests. This can happen when an application provides an API to which many clients
are connecting. To prevent this, you’ll implement rate-limiting on the API side of
things, limiting users to only 100 API requests per hour.
The way you’re going to do this is to add a new field to the users table that stores a
count of how many requests the user has made per hour. To reset the user’s count
back to zero, you’ll create a method that finds only the users who’ve made requests in
the last hour and reset their counts.
13.3.1 One request, two request, three request, four
Currently in app/controllers/api/v1/base_controller.rb you’ve got code that only
checks if the token specified is correct, and if so, assigns a user to the @current_user
variable:
def authenticate_user
@current_user = User.find_by_authentication_token(params[:token])
unless @current_user
respond_with({ :error => "Token is invalid." })
end
end
You’ll now be able to do whatever you wish to this user object in an API request. First,
you’re going to make sure that it’s incrementing the request count for a user whenever
they make an API request. For this, you need a field in the database to keep a
track of user API requests. You’ll generate a migration using this command
rails g migration add_request_count_to_users request_count:integer
This migration will do exactly what you say it should do: add a field called
request_count to the users table. You’ll need to modify this migration slightly so that
the field defaults to 0, which you can do by replacing this line in the new migration:
add_column :users, :request_count, :integer
with this:
add_column :users, :request_count, :integer, :default => 0
14 6000 tickets, as of this writing.
377