CS457 - System Performance Evaluation - Winter 2008

Questions and Comments

  1. Office hours for A1.

Lecture 11

Measuring Performance


What I have called a log is usually called a trace, which is


The code inserted to generate traces.


What other reasons might you have for wanting to measure performance?

What do we try to measure

  1. Arrival and departure times
  2. Processor activity, which can give service times
  3. Other resource activity
  4. Failures

Levels of Measurement

  1. Profiling tools
  2. Application code
  3. Operating system
  4. Kernel
  5. Hardware

The Big Question

How much does the introduction of monitoring software influence the performance of the application.

  1. Event-driven monitors
  2. Sampling monitors

Analysing Data

You have some data. What next?

  1. Can you see any patterns? Exploratory data analysis.
  2. Are the patterns real?
  3. How big are the patterns?
  4. Does it matter? Should you do anything about it?

Reprise the patterns we saw in the application of Little's Law.

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