After doing some performance tests we see that whenever we reach a certain amount of messages the application starts to fail since there are not enough queue sessions (javax.jms.JMSException: Could not create a session: IJ000453: Unable to get managed connection for java:/JmsXA).
This error is specifically related to the JmsXA JCA connection factory and not a statement about a lack of sessions in the server at large. The solution to this problem is to increase the size of the connection pool via <max-pool-size> and <min-pool-size>. Unfortunately you have to have a version of AS7 which includes https://issues.jboss.org/browse/AS7-4330 (which 7.1.1 does not). You'll either have to use a nightly build or pull JBoss AS and build it yourself to get the fix at this point since there is no release which contains it.
Am i doing something wrong? Is this not the propery i need to change?
You are not changing the proper setting. See my previous answer for more details.
Actually i was changing the right values, i was just compiling the wrong code
I got it working so thanks anyway.