Re: Distributive Computing

From: Darin Perusich <Darin.Perusich@cognigencorp.com> Subject: Re: Distributive Computing Date: Thu, 11 Oct 2001 12:16:13 +0000 Setting up a distributed environment depends on your needs. Are you going to be running lots of NONMEM jobs all the time, or just a few now and then? How much money can you spend; it's always as little as possible right? In many cases, depending on the application, using some big SMP machine will be the best route. This is not the case with NONMEM as it is single threaded and cannot take advantage of multiple cpu's; the NONMEM processes just bounce from cpu to cpu and nothing is gained. Would you rather buy a 4 processor machine that will cost $20,000+ or twenty $1000.00 machines? Let's look at a few things that need to be considered. 1. NONMEM run time - In many cases, runs can go for hours, days, even weeks. The underlying platform, hardware, and OS must be reliable. If uptime is a concern, the system should be unix or linux. 2. Computing hardware - The output of NONMEM runs differ between processor architectures. Running the same job on the x86(Intel) and SPARC(Sun) platforms will give hugely different results; therefore, all the machines must be of the same architecture. 3. Compilers - As with the hardware, compiling NONMEM with different compilers gives different results, even between different versions of the same compiler. There is also licensing and pricing issues; GNU is free and runs on every OS whereas many other compilers cost upwards of $1000/seat. 4. Licensing issues for NONMEM, compilers, operating systems, etc. - At a minimium, you'll have to purchase enough licenses for NONMEM; everything else can be done with free tools. 5. Management - The less you have to do the better, especially when you have many machines. This goes back to my first point; as an administrator, I'd need this to be as reliable as possible - having machines "blue screen" for no reason would not be acceptable to me or users. Once a machine has been deployed, it shouldn't need to be touched. What about deploying new systems; do you want to spend half a day setting up the systems? 6. Job deployment - In such an environment, this is one of the most important things. How do i get job 'abc-123' out to machines x, y, or z? These are just a few things to think about. The technical aspects and difficulties run hand-in-hand if you ask me. Someone looking to implement a distributed network of workstations should have a solid grasp of networking, OS deployment, and at least know how to use NONMEM. -- Darin Perusich Unix Systems Administrator Cognigen Corp. darinper@cognigencorp.com