Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!cis.ohio-state.edu!tut.cis.ohio-state.edu!ucbvax!SHUM.HUJI.AC.IL!dalia From: dalia@SHUM.HUJI.AC.IL (Dalia Malki) Newsgroups: comp.sys.isis Subject: looking for real-life examples of isis-groups Keywords: overlapping groups, semantics, causality Message-ID: Date: 12 May 91 10:35:26 GMT Sender: daemon@ucbvax.BERKELEY.EDU Distribution: comp Organization: The Hebrew University of Jerusalem, Israel Lines: 39 I would appreciate replies from ISIS users out there concerning the group services given by ISIS: I would like to assemble some real life examples where inter-group dependence arises. It appears that ISIS algorithms are much complicated by the possible existence of multiple, overlapping groups. This complication arises only if there is causality dependence among them. Intuitively, it seems like the right concept. To be more specific, Ken Birman commented in previous correspondence: > Yes, we do believe that causality is important when multiple groups > overlap. The problem is that asynchronous updates create the > obligation to enforce causality when their may be multiple communication > routes out of and back into a group. In systems with an "object oriented" > structure or systems where a server is made of programs that subscrive > to other servers, one often sees large numbers of groups overlapped in a > way that can raise this issue. If you have such need in your application, could you please send me a description of it, including the general structure and where inter-group dependency occurs. Please emphasize why you need multiple groups instead of, for instance, one big multicast group for all related parties. please mail the replies directly to me, and I promise to make a summary of the interesting ones and post it in the news group for the public benefit. Thanks in advance, - Dalia Malki ------------------------------------------------------------ E-mail: dalia@humus.huji.ac.il Dalia Malki Computer Science dept., The Hebrew University of Jerusalem, Givat Ram, Jerusalem 91904 Israel