Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!utgpu!water!watnot!watmath!clyde!rutgers!sri-spam!ames!ucbcad!ucbvax!CLARKU.BITNET!DHASKIN From: DHASKIN@CLARKU.BITNET.UUCP Newsgroups: mod.computers.vax Subject: RE: DECserver software question (a different one) Message-ID: <8703232212.AA21108@ucbvax.Berkeley.EDU> Date: Mon, 23-Mar-87 08:21:00 EST Article-I.D.: ucbvax.8703232212.AA21108 Posted: Mon Mar 23 08:21:00 1987 Date-Received: Wed, 25-Mar-87 00:52:31 EST Sender: daemon@ucbvax.BERKELEY.EDU Distribution: world Organization: The ARPA Internet Lines: 37 Approved: info-vax@sri-kl.arpa Christopher D. Russell asks: > Here's the problem. I want to set up the DECserver so that the user will > say "Connect Cluster". It is my understanding that the DECserver will then > connect the user to the machine that is least heavily used at the time. > The problem that I forsee is that the machine that the DECserver determines > is "least heavily used" will be a VAXstation with two users on it (all our > VAXstations have a two user maximum). I can't imagine that the DECserver > would be smart enough to avoid this, so it would dump the user to the > VAXstation, which would then, in turn, say "sorry, maximum number of logins > reached" and dump the user back to the DECserver. Voila. The user is > locked out of the cluster. Huh? I can't locate the correct documentation right now, and *possibly* the server software will work differently with the VAXstations, but the selection algorithm (at least with 5.1) with a LAT service is not a straight number-of-current-users, but is based on available CPU time versus number of users or something similar (I remember seeing the exact algorithm but can't locate... if someone else does, please forward to Chris). We use many servers in a cluster of 1 8500 and 2 750s, and even though the 8500 usually has 4-6 times the number of active processes as either of the 750s, the servers still prefer it much more, except in a real crunch situation. One usually has to explicitly request one of the 750s to be assigned there. Denis W. Haskin Manager, Technical Services ------------------------------------------------------------------------ DHASKIN@CLARKU.BITNET Office of Information Systems (617)793-7193 Clark University 950 Main Street Worcester MA 01610 "Anyone who _moves_ before Most Holy comes back out will spend the rest of eternity sipping lava through an iron straw." - Cerebus