java - Any way to share session state between different applications in tomcat?

Question

We want to split a working application in two different .war files in order to be able to update one app without affecting the other. Each webapp will have different a UI, different users and different deploy schedule.

The easiest path seems to be sharing the same session, so if app A set session.setAttribute("foo", "bar") app B will be able to see it.

Is there a way to share the HttpSession state for both apps in the same Tomcat instance?

Our app is running on a dedicated Tomcat 5.5, there are no other apps running on the same tomcat instance, so any security concerns regarding the session sharing are not a problem. We're running multiple Tomcat instances, but the balancer is using sticky sessions.

If it's not possible or this session sharing is a really bad idea please leave a comment.

Answer 1

You should not share HttpSession; but you can share other objects. For example, you can register an object via JNDI and access the same object in all your apps (databases use this to pool connections).