JRuby, Rails, and Torquebox

GR DevDay November 2011

fletcherm.github.com/gr_dev_day_2011

www.atomicobject.com/pages/Presentations

Ruby interpreter on the JVM

Demo!

Techs

Java and the JVM

JRuby

started with version 1.0 (2007)

Write Ruby

class ConfigurationFacade
  def method_missing(name, *args, &block)
    @config[name.to_s]
  end

  def capital_investment
    @config["capital_investment"].present?
      ? @config["capital_investment"]
      : 0
  end
end

Interface with Java

class AgingReportView
  def view
    @table_model = ReadOnlyTableModel.new
    @aging = JTable.new(@table_model)
    @aging.row_selection_allowed = false
    @aging.cell_selection_enabled = true
  end
end

Cross-pollinate for maximum goodness

def invoke_later(&block)
  if javax.swing.SwingUtilities.
                 is_event_dispatch_thread
    block.call
  else
    ...
  end
end

SwingUtilities.invoke_later(Runnable.impl do
  begin
    block.call
  rescue Exception => ex
    puts ex.message
    puts ex.backtrace.join("\n")
  end
end)

def add_row(row)
  invoke_later do
    @table_model.add_row row.to_java
  end
end

def clear_rows
  invoke_later do
    @table_model.clear
  end
end

RSpec

Substance

Apache Batik

Java scenegraph

JFreeChart

Beta distribution

Bouncy Castle

YAML

NSIS - Windows installer

Launch4J - Windows Java app launcher

.app bundle on Mac

shell script on Linux

Rails and Torquebox

(skipping Rails introduction)

web server

JBoss Application Server

caching

Infinispan

alternative to memcached

config.cache_store = :torque_box_store

User.transaction do
  User.create(:username => 'Kotori')
  User.transaction do
    User.create(:username => 'Nemu')
    raise ActiveRecord::Rollback
  end
end

credit torquebox website

TorqueBox.transaction do
  User.transaction do
    User.create(:username => 'Kotori')
    User.transaction do
      User.create(:username => 'Nemu')
      raise ActiveRecord::Rollback
    end
  end
end

credit torquebox website

Building a Rails app with Torquebox and JRuby

the recipe

stirring the pot

unpack Torquebox and remove its JRuby

unpack your JRuby

use bundler to install your gems into this JRuby

>> rake torquebox:archive

=> knob

copy knob and JRuby into Torquebox

copy in support scripts (startup, shutdown, etc)

tar it up

consume

scp archive to test machine with only Java and database

unpack archive and launch app in production mode

run acceptance tests against the running server

passed? publish the artifact and mark it green

ups and downs of these technologies

(see previous slides for goodies)

used MongoDB + Mongoid with no issue or extra work required

many other rubygems with no issue

things that sucked

export JAVA_OPTS="-d32"

JRuby + Rails loading problem or JVM problem?

Torquebox slow to start

usually only an issue once a day

somewhat slow to reload in dev mode

blazing fast reloads in production mode

battling the environment