A status update on JRuby, covering compatibility, Rails, and next-gen performance numbers. JRuby is currently the fastest way to run Rails apps, and we're doing work to make it even faster in the future.
I brought some American craft beers to give away! • Try running something on JRuby, show me, and take your pick: • Bender: oatmeal brown ale • Furious: dark American IPA • Foggy Geezer: New England IPA
while, gathering information • Just-in-time (JIT) compiler compiles hot code to JVM • JVM turns that into optimized native code • Heavy dependence on JVM to optimize well • Newer JVM JITs showing great promise!
Practically useless • Like judging a person by how much they can bench press • JRuby has won microbenchmarks for years, never faster on Rails • Easier to isolate speciﬁc measurements • Great for exploring new runtimes and tech
JVM see through all the dynamic bits of Ruby • Added in Java 7, with much input and testing from JRuby • Steadily improving performance, reducing overhead • -Xcompile.invokedynamic • May be default soon!
2006 • Almost as long as Rails has existed! • Thousands of JRoR instances around the world • JRuby 9000, Ruby 2.4, 2.5 work slowed down Rails support • Rails 5.0 not supported for at least a year • ActiveRecord suffered the most
No C extensions, no -devel packages, no headers or compiling • Rebooted last year to reduce maintenance hassle • 1:1 match with Rails versions (e.g. Rails 5.1 = ARJDBC 51.x) • SQLite3, MySQL/Maria, PostgreSQL • Sharing 90%+ of code with Rails