Today... err, yesterday, I began looking at Distributed Ruby, or DRb. DRb is a system for allowing Ruby processes to communicate with each other. Really, it's a client/server thing.

This is part of the Peer Pressure Learning 30 series. To learn more about what in the hell that means, see the intro to the series, A Good Time To Learn.

Installation

NOTHING! DRb is included in Ruby 1.8+.

Resources

The DRb Site

I started with what I believe to be the DRb site. In particular, the Introduction to DRb was a pretty straightforward way to get started. If your eyes are up to the task of actually reading the content on this site, the content can be quite informative.

What I Think I Now Know

DRb is a lot of fun to play with, for some reason. I don't really think the DRb site quite does it justice, actually. There are many possibilities. For instance, distributed FizzBuzz!

Server:

 1 #!/usr/bin/env ruby
 2 #
 3 # Server
 4 
 5 require 'drb'
 6 
 7 class FizzBuzz
 8   def initialize(range = 1..100)
 9     @range = range
10   end
11 
12   def range=(home)
13     @range = home
14   end
15 
16   def fizzbuzz
17     @range.to_a.map do |num|
18       result = ''
19       result = 'Fizz' if num % 3 == 0
20       result += 'Buzz' if num % 5 == 0
21       result.empty? ? num : result
22     end
23   end
24 end
25 
26 DRb.start_service 'druby://:9000', FizzBuzz.new
27 puts DRb.uri
28 
29 trap("INT") { DRb.stop_service }
30 DRb.thread.join

Client:

 1 #!/usr/bin/env ruby
 2 #
 3 # Client
 4 
 5 require 'drb'
 6 
 7 DRb.start_service
 8 fb = DRbObject.new nil, 'druby://:9000'
 9 fb.range = 1..200
10 fb.fizzbuzz.each {|r| puts r }

Of course we need to access FizzBuzz answers from a remote client, right? Place each of those in an executable file (e.g. the server script in server.rb, the client script in client.rb). Then, in one terminal window, run ./server.rb, and in the other run ./client.rb. MAGIC!

I really recommend giving the Introduction to DRb a quick skim, at least. It's really not too complicated, as long as you're awake enough to read it clearly.

I'm so close. I will be doubling up tomorrow, as tomorrow marks the final day of the PPL30. I swear, I'm going to finish. Success is within my grasp, and I shall not allow accolades of such great import slip feebly from my fingers! ... Yup, so, Schema and MacRuby.