patas.ling.washington.edu Condor Cluster

What is it?

Condor is a batch-oriented clustering system. Jobs are submitted into a job queue, matched with an available compute node, and run on that node.

How is it different from OpenMosix?

If you've used our Pongo OpenMosix cluster, you may be wondering how Condor differs. There are some key differences:

• OpenMosix attempts to be transparent to the user. Processes are all run on the head node, and they are then migrated to available compute nodes. By contrast, Condor requires the user to set up the job specifically to be run on the cluster. (The software, however, does not need to be cluster-aware.)
• OpenMosix jobs can be interactive; Condor jobs must run without user interaction.
• OpenMosix cannot migrate jobs that use threads or shared memory, and jobs sometimes crash during migration. Condor can run any software that can be set up to run non-interactively, and it will have the same stability it would on a stand-alone system.

How do I get an account?

If you have a pongo account, you already have access to the Condor cluster. ssh to patas.ling.washington.edu.

How do I use it?

Visit the HowToUseCondor Wiki page for a quick introduction.

Software notes

This section documents differences between the software loaded on patas and the software loaded on pongo.

• The base operating system is Red Hat Enterprise Linux Server 5, instead of Debian Stable.
• We are running a 64-bit operating system, with compatibility libraries to support 32-bit software.
• The 64-bit version of Sun's Java Virtual Machine is installed. This provides nearly 4 gigabytes of heap space, instead of 2 gigabytes in the 32-bit version. This is also a server JVM, meaning it performs some extra optimization. This results in slower startup times but long-running jobs complete faster.

Software on pongo that is not yet installed on patas

This should only be a temporary situation -- most of these will eventually make it onto the new cluster.

• The NLP_TOOLS directory from pongo is not currently installed.
• SRILM (Regression tests fail)
• Lingua-BrillTagger, Lingua-Wordnet Perl modules ("make test" fails)
• Text-NSP-1.01 Perl module ("make test" fails)
• WordNet-Similarity (won't build) -- fixed & installed, 16-JUL-2007

Patas? What's that?

Patas monkeys are slender, ground-dwelling primates found in central Africa. They can run faster than any other primate, reaching speeds of up to 55 km/hr.

-- DavidBrodbeck - 13 Jul 2007