Jboss server was throwing an Exception all of a sudden "You are trying to use a connection factory that has been shut down: ManagedConnectionFactory is null". No changes made to the datasources, prior to this. Everything got normal after a server bounce...
What are all the possibilities for this?
After digging into this issue further, we found there was a dependency which was not responding, that increased the thread count.There was also memory leak. Due to this server got restarted by itself... From the logs it was clear the server got restarted and that could be the reason this exception. As mentioned in the above comments the search pages from the google shows that this exception could be thrown when there is issue loading the datasources... Everything was fine after bouncing the server... Thanks all...