we are experiencing some performance problems in our portal (based on jboss portal 2.6.4, running on java 6). We have 8 or 9 portlets running in the portal. When only one user is accessing the portal, all works OK: the portal answer quickly an so on. But, when there are 4 or 5 users concurrently, the portal takes a long time in anwering...it seems that only when the request of one user has been anwered, the one of the other user is processed and so one.
We have been analyzing this behaviour and it seems the only one instance of the java portlet class is created and shared among all the users accessing that portlet.
My question is: is this normal? can this be configured to work in other way? If this has to be in this way..how can we implement our code so the performance is increased? (inside the portlet there are functions which takes sometime in executing).
I hope someone can help us.