Jeff Longland

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Posts Tagged ‘BbW12 devcon

#BbW12 DevCon – A Cookbook for Administration of Learn

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  • Presenter: Steve Feldman
  • “Following someone else’s instructions can be pretty dangerous”
  • “Anyone can cook, but it takes more effort to be a chef.   The same applies to running an enterprise system.” – here, here!
  • Using the 1854 Broad Street cholera epidemic as an example, Steve discussed the value of statistics and visualization.  Snow was only able to make his argument after appropriately supporting it.
  • In application management, we need to look at data in many ways.  Averages on their own aren’t enough.  Look at:
    • Percentiles
    • Averages plus 2 standard deviations
    • Histograms – tell a story about groups of outliers
    • Scatterplots – tell a story about individual outliers
    • Associate different types of data
  • Look for the outliers and find out what was going out.  What was the user doing to cause the CPU spike?
  • What have we learned?
    • It’s dangerous to use past experience without considering the data of the present.
    • It’s dangerous to ignore data.
    • Problems cannot be solved simply with extra capacity.
    • Looking at time series statistical averages can be just as dangerous.
    • Seeking out statistical anomalies as they will tell us so much about how bad or defective the user experience truly is.
  • Slides posted on slideshare.

Written by jlongland

July 13, 2012 at 9:41 pm

Posted in Blackboard DevCon 2012

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