It’s a Bird…
It’s a Plane…
DigitalSonic
No, it’s Superman Oct. 2009

How many Rails developers
have Java knowledge?

• The Best of JVM
• It’s Just Ruby
• Platform Independent

Have a Try
• Download the latest JRuby distribution
• Unpack
• Add the bin path to $PATH or %PATH%
• Test it
jruby –v
jirb
jirb_swing

Ruby => JRuby
• ruby  jruby
• C backend libraries  Java backend libraries
• …
• gem  jruby –S gem
• rake  jruby –S rake
• rails  jruby –S rails

Ruby on Rails => JRuby on Rails
adapter: mysql
mongrel
RMagick
…
adapter: jdbcmysql
mongrel-jruby
RMagick4J
…

Both Rails and Java EE projects are
running in the same Java AS?

Warbler
• Warbler is a gem
that makes a .war
file out of a Rails,
Merb, or Rack-based
application.
http://kenai.com/projects/warbler

Rails in Java AS
• Tomcat
• Jetty (jetty-rails)
• Glassfish v2 / v3 (gem)
• JBoss (JBoss-Rails)
• …

Rails in Java AS (cont.)
• Connection Pool
• Load-Balance
• Larger JVM Memory Size
• Server JVM
• Latest JDK
• Sun JDK / BEA JRockit ?

Showcase: Blog
• Getting Started with Rails
http://guides.rubyonrails.org/getting_started.html
• Step by Step
jruby -S rails blog
Modify database settings
jruby -S warble config
Modify config/warble.rb
jruby -S warble war
Deploy into Tomcat

Showcase: Blog (cont.)

Showcase: Monitor
• Tomcat Monitor Tools
PSI Probe (Lambda Probe)
Hyperic HQ
• VM Monitor Tools
JConsole
VisualVM
JRockit Mission Control

Showcase: Monitor (cont.)

Showcase: Monitor (cont.)

Showcase: Simple Tuning
• VM
 -Xmx768m -Xms768m -Xmn256m -XX:MaxPermSize=128m -
XX:PermSize=128m
• Tomcat Connector
 maxThreads="1024" minSpareThreads="32" maxSpareThreads="128"
enableLookups="false"
• JNDI Connection Pool
 For my laptop only, not for production environment
 Some parameters are set without measurement

Showcase: Simple Tuning (cont.)
Time Taken For Tests (s)
200 185.817
180
160 rails 2.2.2
140 activerecord-jdbc-adapter 0.9.2
120 106.742
100
jdbc-mysql 5.0.4
80 64.735 warbler 0.9.14
60
40
18.561 12.367 6.748
20
0
Mongrel Tomcat Tomcat-Optimized
ab -n 100 -c 10 (ms)
Total n100 c10 Total n1000 c100
2500 2396
2000 1784 1805
Ubuntu 8.10, kernel 2.6.27-14-generic
1500
JDK 1.6.0 Update 10 1202
JRuby 1.3.1 1000 786
641
Apache Tomcat 6.0.20
500 266
Mongrel 1.1.5 241
142
0
Min Avg Max
Mongrel Tomcat Tomcat-Optimized

Reference
• http://jruby.org
• http://rubyonrails.org/
• http://kenai.com/projects/jruby/
• Practical JRuby on Rails Web 2.0 Projects
• JRuby Cookbook

Q&A