High Performance Linux Clusters with OSCAR, Rocks, OpenMosix, and MPI [Electronic resources] نسخه متنی

Chapter 11. Scheduling Software

Basically, scheduling software lets you
run your cluster like a batch system, allowing you to allocate
cluster resources, such as CPU time and memory, on a job-by-job
basis. Jobs are queued and run as resources become available, subject
to the priorities you establish. Your users will be able to add and
remove jobs from the job queue as well as track the progress of their
jobs. As the administrator, you will be able to establish priorities
and manage the queue.

Scheduling software is not a high priority for everyone. If the
cluster is under the control of a single user, then scheduling
software probably isn't needed. Similarly, if you
have a small cluster with very few users or if your cluster is very
lightly used, you may not need scheduling software. As long as you
have more resources than you need, manual scheduling may be a viable
alternativeat least initially. If you have a small cluster and
only occasionally wish you had scheduling software, it may be easier
to add a few more computers or build a second cluster than deal with
the problems that scheduling software introduces.

But if you have a large cluster with a growing user base, at some
point you'll want to install scheduling software. At
a minimum, scheduling software helps you effectively use your
hardware and provides a more equitable sharing of resources.
Scheduling software has other uses as well, including accounting and
monitoring. The information provided by good scheduling software can
be a huge help when planning for the future of your cluster.

There are several freely
available scheduling systems from which you can
select, including Portable Batch System (PBS),
Maui, Torque, and
Condor. OSCAR includes Portable Batch System
(PBS) along with Maui. Torque is also available for OSCAR via
opd. Rocks provides a PBS roll that includes
Maui and Torque and a second roll that includes
Condor.
Since PBS is available for both OSCAR and Rocks,
that's what's described in this
chapter. (For more information on the alternatives, visit the web
sites listed in the Appendix A.)

PBS is a powerful and versatile system. While this chapter sticks to
the basics, you should keep in mind that there is a lot more to PBS
than described here. Look at the

Administrator
Guide to learn more, particularly if you need help with
more advanced features.