I'm actually using it in a small side-project I implemented a couple of weeks ago. (http://playas.io http://playas.io) It uses Rails 4 [0], JRuby 1.7.4, postgre

I'm actually using it in a small side-project I implemented a couple of weeks ago. (http://playas.io http://playas.io) It uses Rails 4 [0], JRuby 1.7.4, postgresql with full text search, one dyno and 10 workers. It is not the first time I'm using JRuby and Puma, I must say I'm pretty happy with it. I had enough with the official documentation, just tweaking the DB pool to fit in the Rediscloud free version constraints. [1] https://devcenter.heroku.com/articles/concurrency-and-database-connections https://devcenter.heroku.com/articles/concurrency-and-databa... [0]: You'll need to download JCE 6 Extensions to get Puma, JRuby 1.7.4 and Rails 4 running in development: http://www.oracle.com/technetwork/java/javase/downloads/jce-6-download-429243.html http://www.oracle.com/technetwork/java/javase/downloads/jce-... [1]: Rediscloud free version gives you 10 connections.