Not that I know of. However, there may be a few settings you can tune to (temporarily) alleviate this situation.
Different documents? Are you sure you aren't publishing too many different documents to too many users (like for instance all docs to everybody because everone has a named CAL and for the sake of simplicity distribution lists specify "All authenticated Users"?)
Or the same document? In QMC, enable "Allow only one copy of Document in Memory". Optionally you can also limit the total number of concurrent sessions, but that will not prevent one user from opening two sessions and thereby blocking another user from starting an own session.
Since there is no real method like the one you are asking for, the only fail-safe solution is to add more RAM to your server...
Hi Peter. Thanks for your answer. We have a 3 large documents being reduced to hundreds of small documents and distributed to hundreds of users. This has always worked fine - but - since my question was asked, we have found out, that the qvs server is erronated and that we have to change it. So - this is the answer to out problems.