I’m releasing my experiments with JRuby and Terracotta, so you can play with JMaglev and contribute some code. The project is in Github.

I had to patch JRuby to make RubyObjects a little less dependent from the JRuby Runtime. It isn’t perfect yet, but is working. The patch against the current jruby trunk (rev. 8091) and the patched jruby-complete are included in the project.

The code in Github is just a TIM (Terracotta Integration Module) with a sample maven project and the JMaglev use-case included. Unfortunately, I haven’t any time yet to upload the TIM to Terracotta Forge. BTW, does anyone know how to do this?

For those who want to reproduce my JMaglev demo, here is a step-by-step. You must have GIT, Maven 2 and the JDK properly installed. It only works on Linux and OS X. Is anyone wanting to contribute support for Windows users?

1. git clone git://github.com/fabiokung/clustered-jruby.git
2. long time waiting, because terracotta-2.7.1 (vanilla) and jruby-complete (patched) are bundled.
3. cd clustered-jruby
4. mvn install (although mvn package is enough)
5. cd jmaglev
6. start the terracotta server:
   lib/terracotta-2.7.1/bin/start-tc-server.sh
7. open another two terminals
8. run the simplified jirb inside them:

cd clustered-jruby/jmaglev
./bin/jmaglev jmaglev.rb

9. Follow the demo. You will be able to share global variables among all jmaglevs:
   

   require 'hat'
   $hat
   require 'rabbit'
   $hat.put(Rabbit.new)
   

10. in the other terminal, try to see the magic hat contents:
    

    $hat
    

I haven’t tested it with rails applications, but right now, it isn’t able to run IRB. I never thought that running IRB could be so hard.

More drawbacks and limitations are being discussed in the JRuby Users Mailing List.

I hope to see many contributions. Happy hacking!