Scaling Rails with JRuby in 2022

Explore the benefits of scaling Rails applications with JRuby in this RailsConf 2022 talk. Discover how JRuby, now supporting Ruby 3.1, offers world-class garbage collection, native JIT compilation, and true parallel threading. Learn to reduce latency and resource costs by hosting a single JRuby process for concurrent users. Gain insights into JRuby's compatibility, JVM benefits, installation process, and deployment strategies for Rails applications. Examine performance improvements in Active Record operations and understand caveats and future improvements. Uncover why JRuby is the only alternative Ruby implementation deployed at scale, powering mission-critical applications worldwide.

Intro
What is JRuby?
Ruby Compatibility
JVM Benefits
JVM Tools and GC
Fun Stuff
JRuby Install
Why JRuby on Rails?
Minimal Config Diffs
Catching Up
activerecord-jdbc-adapter
bundle install
Dealing with C Extensions
Deploying JRuby on Rails
Scaling Rails
Baseline Rails App
Caveats
Active Record Performance
Select Performance
Update Performance
True Story
Warmup Time
JRuby Flag: --dev
Future Improvements
JRuby Future
JRuby on Rails Future