The fact that the users have logged out is not enough to release the memory. The cache is still active and keeps the selections and results of previous sessions. And this is the designed behavior.
In other words: The fact that the QVS uses memory is not a sign that something is wrong. Quite the opposite, in fact.
Let me explain how it works.
QlikView catches all the actions of the users. So when a user is using the application, it will consume the RAM, because the application is being utilized.
Now when there are no sessions going on that time also QlikView keep the data in RAM, the reason is user might again open the report and this time the performance will be better for him, because the data is already in RAM.
Now you might have question that what if full RAM is utilized.
In such case QlikView will remove the earlier or older catch data, so even tough you see the full utilization of RAM, only few % of RAM is being utilized. So you shouldn't worry that your Server will crash or have any other issue.
You can also set the limit of the Memory which can be used by QlikView.
For this you should go to QEMC -> System -> Setup ->QlikView Serve -> Performance
Here you will see the option of Working Set.
You can set the Minimum and Maximum % of RAM which should be used by QlikView.
I have changed the settings as u have suggested.I ll just monitor for some time if this has worked. Mean while i have 2 more queries regarding performance.
1> If there are 4 users active in server using 4 diff application and the overall qvs usage is 40 gb, being an administrator can i know which application is taking how much gb ram in the server?
2> If i know a particular application is taking higher amount of RAM, then can i kill that particular session?