Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!watmath!clyde!cbatt!ucbvax!HI-MULTICS.ARPA!MHJohnson From: MHJohnson@HI-MULTICS.ARPA.UUCP Newsgroups: mod.computers.vax Subject: re: Load balancing on a cluster Message-ID: <870203043404.985966@HI-MULTICS.ARPA> Date: Mon, 2-Feb-87 23:34:00 EST Article-I.D.: HI-MULTI.870203043404.985966 Posted: Mon Feb 2 23:34:00 1987 Date-Received: Wed, 4-Feb-87 01:51:40 EST Sender: daemon@ucbvax.BERKELEY.EDU Organization: The ARPA Internet Lines: 22 Approved: info-vax@sri-kl.arpa About cluster queues... it appears to me that batch and print jobs will go to the first queue associated with a generic queue unless it is busy. Then the second queue (and so on) will be used. This at least holds true for the print queues. On my system, the one used first has a name starting with G and the second starts with D. Batch queues area little more complicated though. If I remember correctly, VMS will choose the `most lightly loaded' queue in preference to the rule above. This means you can make a generic batch queue and make one queue for each CPU for batch that varies in size based upon the performance of the CPU. For example, if you have a 5 slot queue on an 8700 and a 2 slot queue on an 8200, the jobs will be allocated in the following order: 8700, 8200, 8700, 8700, 8200, 8700, 8700. The second job always goes on the smaller queue (zero load is less than any load...) if the larger queue has any jobs running. It would be nice to have load balancing in a more general way but from I understand about VMS, it would take a LOT to implement. A number of things such as mailboxes, shared memory, etc just don't work between cluster members at this time. --Mark