Our current app runs in a single JVM.

We are now splitting up the app into separate logical services where each service runs in its own JVM.

The split is being done to allow a single service to be modified and deployed without impacting the entire system. This reduces the need to QA the entire system - just need to QA the interaction with the service being changed.

For inter service communication we use a combination of REST, an MQ system bus, and database views.

What I don't like about this:

• REST means we have to marshal data to/from XML
• DB views couple the systems together which defeats the whole concept of separate services
• MQ / system bus is added complexity
• There is inevitably some code duplication between services
• You have set up n JBoss server configurations, we have to do n number of deployments, n number of set up scripts, etc, etc.

Is there a better way to structure an internal application to allow modular development and deployment while allowing the app to run in a single JVM (and achieving the associated benefits)?