From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <3AE047EB.D8533377@badtux.org> From: Eric Lee Green MIME-Version: 1.0 To: 9fans@cse.psu.edu Subject: Re: [9fans] Plan9 vs Beowulf References: <20010419234118.A986@localhostnl.demon.nl> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Date: Fri, 20 Apr 2001 07:30:03 -0700 Topicbox-Message-UUID: 8755aae2-eac9-11e9-9e20-41e7f4b1d025 William Staniewicz wrote: > Is there any comparison between a Plan 9 network > and a Beowulf cluster? Not really. There is no such thing as a "Beowulf cluster" (and I say that having designed and implemented one in the late 1990's when I worked for Linux Hardware Solutions). What there is, is a set of management tools to allow doing various system administration tasks in parallel (rather than having to log into 1024 different computers!), and several different hacks to the standard Unix "fork"/shared memory model to allow that program to be "forked" to a different node on the network and allow that memory to be "shared" with other computers on the network rather than just be local. It isn't really shared, of course. Programs have to be specially compiled to use one of these memory managers and must have the calls added to ship the memory. And it really does not work very efficiently at all. That's why this is mostly used for things like signal processing where the task can be broken up into dozens of independent tasks that communicate only when they hit the edge of their little piece of the big picture. It is not a general purpose clustering technology. A Plan 9 network is a set of services on a network, but the services communicate via standard networking protocols, not via a fake Unix shared memory manager. So Plan 9 is basically a different beast. Each Beowulf node is in fact a standalone system, running all services that it needs to execute programs, and the programs are what run in a distributed fashion. A Plan 9 node may run services distributed all over the network, but the services themselves aren't parallelized across nodes, and programs you run on a Plan 9 network run on a particular node. -- Eric Lee Green http://www.badtux.org mailto:eric@badtux.org Phoenix Branch -- Eric Conspiracy Secret Labs Cruisin' the USENET since 1985