Path: utzoo!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!rutgers!mailrus!uwm.edu!psuvax1!psuvm!EVALUN11!MONTANAN From: MONTANAN@EVALUN11.BITNET (Rogelio Montanyana) Newsgroups: bit.listserv.vmxa-l Subject: Looking a way to limit interactive CPU utilization Message-ID: Date: 6 Feb 90 23:30:35 GMT Sender: VM/XA Discussion List Reply-To: VM/XA Discussion List Lines: 34 Approved: NETNEWS@PSUVM Gateway Dear colleagues: We have a 3090 that is actively being used by a very wide community of people in our University. As System Manager I am responsible of providing a fair share of computing resources to all of them. We are experiencing a big problem because we have some number crunchers that would use as much CPU power as they can access, and as far as I know there is no way in VM/XA SP2 to limit the maximum CPU time for an interactive user. In an attemt to avoid the typical situation where every user executes his/her program interactively (being Disconnected) instead of using the batch queues, we have modified the priorities (SHARE parameter in XA) in order to make batch executions faster than interactive ones. This solution has the undesired side effect of effectively reducing the performance for users that actually do interactive work (short executions, compilations, for instance). I have been thinking about writing a REXX program that would run in a disconnected service machine, and whose main task would be to have a look at the system from time to time (every three minutes, for example); that program would follow (using the CP INDICATE QUEUE command) those CPU bound users, and would reduce their SHARE progressively; of course, certain users (i.e., batch machines) would be excluded from the process. Because I do not want to reinvent the wheel, I first want to ask if anybody has already written something similar. I would also be very glad to accept comment and suggestions from other people. Thanks to everybody, Rogelio Montanana System Manager Valencia University BITNET: MONTANAN at EVALUN11