Ola Bini: Programming Language Synchronicity

As I mentioned in my last post, that server/client thing wasn't the only thing I worked on during the flight. I also did a very useful hack of mongrel_cluster, and turned it into mongrel_jcluster. It's not very large changes, actually... Almost everything is the same, except that this mongrel plugin only runs in JRuby, and will start several mongrels in the same JVM.

jruby -S gem install mongrel_jcluster
cd your_rails_app
jruby -S mongrel_rails jcluster::configure -p 4000 -N 3 -e production -R 20202 -K thesecretkey
jruby -S mongrel_rails jcluster::start

The only difference in the configuration parameters are -R and -K which is the JRuby server port and key respectively. Now, after executing these commands, it will take some time for the mongrels to get online, so be patient (or monitor the progress in the log-files generated).

I need to warn you that this is still quite experimental and not guaranteed to work in any way. =) But it does for me.

Another thing, if you start Mongrel in production mode, the defualt Rails front-page will give you an error if you try to get at the properties. This is the expected behavior in production mode, though, and nothing wrong with JRuby.