Wednesday, July 29, 2015

Hockey Elbow and Other Response Time Injuries

You've heard of tennis elbow. Well, there's a non-sports, performance injury that I like to call hockey elbow. An example of such an "injury" is shown in Figure 1, which appeared in a recent computer performance analysis presentation. It's a reminder of how easy it is to become complacent when doing performance analysis and possibly end up reaching the wrong conclusion.

Figure 1. injured response time performance

Figure 1 is seriously flawed for two reasons:

  1. It incorrectly shows the response time curve with a vertical asymptote.
  2. It compounds the first error by employing a logarithmic x-axis.

Sunday, July 26, 2015

Next GCaP Class: September 21, 2015

The next Guerrilla Capacity Planning class will be held during the week of September 21, 2015 at our new Sheraton Four Points location in Pleastaton, California. Early bird rate ends August 21st.

During the class, I will bust some entrenched CaP management myths (in no particular order):

  • All performance measurements are wrong by definition.
  • There is no response-time knee.
  • Throughput is not the same as execution rate.
  • Throughput and latency metrics are related — nonlinearly.
  • There is no parallel computing.

No particular knowledge about capacity and performance management is assumed.

Attendees should bring their laptops as course materials are provided on CD or flash drive. The Sheraton provides free wi-fi to the internet.

We look forward to seeing you there!