Managing performance
To manage the performance of a system,
you normally try to share the available
resources
equally between its users.
However, different users perceive
performance according on their own needs and the demands of the
applications that they are running.
If they use interactive programs,
response time
is likely to be their main index of performance.
Someone interested in performing numeric analysis may only be
worried about the turnaround time for off-line batch mode processing.
Another person may wish to perform
sophisticated image processing in real time
and requires quick access to graphics data files.
You, as the administrator, are interested in maximizing the
throughput
of all
jobs
submitted to the system -- in fact,
keeping everyone happy.
Unfortunately, such differing requirements
may be difficult to reconcile.
For example, if you administer a single standalone system,
you may decide that your main priority
is to improve the interactive response time.
You may be able to do this
by decreasing the overall workload at peak usage times.
This would involve scheduling some work
to run as batch jobs at quieter times,
or perhaps restricting simultaneous access to your system
to a smaller number of users.
However, in speeding up your system's response,
you now have the additional problem of decreased throughput,
which results in the completion of fewer jobs,
potentially at critical times.
In pursuing any particular performance improvement policy,
there are always likely to be trade-offs,
especially in a situation where resources are at a premium.
The next section covers the setting
of realistic performance goals
as the first step in improving
the performance of your computer system.
You are then given a method
for observing and tuning a system.
Next topic:
Tuning methodology
© 2003 Caldera International, Inc. All rights reserved.
SCO OpenServer Release 5.0.7 -- 11 February 2003