A buildpack to fast and easy use JRuby on Heroku. Just create a Heroku app like this:
heroku create --buildpack https://github.com/jruby/heroku-buildpack-jruby.git
web: bin/puma -p $PORT -e $RACK_ENV
Note: You do normally not want to use
bundle exec with JRuby. Use the binstubs (in
Gemfile with a "ruby" line is required. So to use JRuby 1.7.4 in 2.0 mode, put this in you
ruby '2.0.0', engine: 'jruby', engine_version: '1.7.4'
If you change Ruby version, ie. JRuby mode, don't forget to update
JRUBY_OPTS. The buildpack can only set environment variables on first push.
$ heroku config:add JRUBY_OPTS="--2.0 -J-Xmx400m -J-XX:+UseCompressedOops -J-noverify"
Otherwise you might end up with errors such as:
Bundler::RubyVersionMismatch: Your Ruby version is 1.9.3, but your Gemfile specified 2.0.0
Example application: github.com/carlhoerberg/heroku-jruby-example
To use another JVM version, eg. 1.7 (recommended), create a file called
system.properties in your root folder with the following content:
Note: Currently, supported versions are 1.6, 1.7, and 1.8. The default is 1.6.
This is the same procedure as for all JVM based Heroku buildpacks: https://devcenter.heroku.com/articles/add-java-version-to-an-existing-maven-app
To get the assets precompiled during slug compilation take the following actions:
Gemfile(and then run
config.assets.initialize_on_precompile = falseto
- (Optional) Replace
config.assets.js_compressor = :closureto
config/environments/production.rb, to get faster compile times.
To get Heroku to pick up Rails logs you have to add the following to
STDOUT.sync = true logger = Logger.new(STDOUT) logger.level = Logger::INFO config.logger = logger
Recommended web servers are:
- Puma - A server written in Ruby, wraps the Ragel parser (from Mongrel)
- Trinidad - A wrapper around Tomcat
- Mizuno - A wrapper around Jetty
A comparison can be found here: carlhoerberg.github.com/blog/2012/03/31/jruby-application-server-benchmarks/
To get the real benefits of JRuby you should enable multithreading, both in the application server of choice as well as in Rails.
--threadsafe flag as a command line argument to Trinidad.
web: bin/trinidad --threadsafe --rackup -p $PORT -e $RACK_ENV
Copyright (C) 2012 by Carl Hörberg
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
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