Anyone scaling jruby tomcat?

ah ah ? Anyon netty a rails app behind apache?

Yes. What specific info are you looking for.

benchmarks - multi-process configuration / multi-interpreter setup / and where the community is with respect to jetty/netty/trinidad etc.

Multi process is automatic with any java app server and does not require any configuration. As to benchmarks for which java app server is faster I do not know off-hand. We have several cloud deployed load balanced apps running on Trinidad, which is based on Tomcat. Trinidad is the present jruby runtime server with the most development effort - it keeps evolving; before that GlassFish was THE app server for jRuby. Ever so often, depending on the load, we just add or remove a node to/from the load balanced cluster.