JSESSIONID suffixed with .undefined

Question

I have a Spring Web MVC application running in Jboss AS 7.1. When I check the session id of the application (by looking at the session cookie using Firebug from Firefox), it has .undefined suffixed with it. For example,

Ur1bLe3UDdWJ9xm0ZDbMfZvJ.undefined

I worked out a sample servlet session program and checked the session id and it is the same. I would like to know why we have .undefined as part of session id? I think this will not have any impact on the application, but wanted to know why the session id is created like this. If anyone knows about this, please clarify.

Answer 1

If I am not mistaken in JBOSS 7.1 the .undefined part is due to the instance-id not being configured in the standalone.xml file.

The following addition to the standalone.xml file would replace the .undefined with a configured text:

<subsystem xmlns="urn:jboss:domain:web:1.1" 
           default-virtual-server="default-host" 
           native="false" 
           instance-id="hostA">

There is also this discussion here: community.jboss.org