CFI 2004 UW A quick overview with lots of time for Q&A and exploration.

Q: What is a cluster? A: A group of machines that can work together to produce results.

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Characteristics  Group of machines  Not necessarily homogeneous  Common set of users  Some sort of batch system

Why do I want one? Ideally your jobs are able to be parallelized and do not require allocation of large chunks of memory.

When do I not want one? When you need large chunks of memory, or when you only need a single fast CPU

What do we have?  marroo - 21 nodes  shiraz - 21 nodes  vidal - 16 nodes

How do I get to them? Accounts - SSH client -

Quick Hardware Specs  SunFire X dual CPU, dual core  2.4GHz Opteron cores  8GB RAM

Filesystems  /home - big, shared  /scratch-net - big, shared  /scratch - local, not so big  Network filesystems on a NAS

Backups There aren’t (yet?) any, so be careful

Power shiraz and marroo have a UPS each backing head nodes and NAS vidal will be getting a UPS to back at least that also

What can I do? They’re Linux boxes, so anything you could normally do on your workstation. Plus a bit more.

Sun N1 Grid Engine Fairly simple setup of batch system, our implementation has only a single queue.

N1GE QuickStart Only on vidal sge-root is /home/N1GE6 Cell name is “default” Important commands are qsub and qstat

Commercial Software CFI grant has allowances for MatLab CPLEX is installed on vidal, arrange for licensing

Free Software Of course, there are lots of packages available for Linux. We have installed R on vidal, along with some packages.

Updates and Security Compute nodes as static as possible Head nodes receive security updates Head node reboots scheduled in advance

Other Stuff Ganglia for rough usage data and trends Head nodes monitored for connectivity Mailing list!

Hopefully this…

… leads to this: Fun in the Sun