Our application is a data cruncher, it's not a public web site, and our controllers/views are just a GUI to control/monitor the process. Memory usage shuts up

Our application is a data cruncher, it's not a public web site, and our controllers/views are just a GUI to control/monitor the process. Memory usage shuts up to 700-800MB per Rails instance but it stays there regardless of how many documents we put through the pipeline. Also our migrations stopped working in test environments - JDBC db adapter would "reset" itself back to mysql MRI gem ignoring database.yml. On CentOS it would happen with all environments, not just test. We were never able to figure out where/how this happens due to extremely dynamic/"magic" nature of AR and Ruby in general, so we're using MRI just to run migrations and we moved to Ubuntu in production to keep JRuby/JDBC happy But my biggest objection to using JRuby in the future is that it's easier to use Java for accessing Java libraries, i.e. using JRuby simply because you need some Java-based OCR package is simply not worth it - my advice would be to use Java to access that API and then interop with MRI somehow, I would do it via HTTP-based REST API between Rails/MRI process and Tomcat-hosted JVM.