Year: 2011

Authors: Doug Terry

Summary

This technical report was a very good read. It was recommended by Joe as part of our quest to better define visualization consistency, and finding the taxonomy of issues we experience in visualizations. Using baseball as a case, the author suggested the different kinds of consistency needs of the different participants. At a glance (without much explicit explanation), they are:

  • Official scorekeeper: read my writes
  • Umpire (officiates a baseball game from behind home plate): strong consistency
  • Radio reporter: monotonic read or bounded staleness
  • Sportswriter: eventual consistency is probably enough, but bounded staleness just to be sure

And here are the consistency guarantees if you have forgotten already!

  • Strong Consistency: See all previous writes.
  • Eventual Consistency: See subset of previous writes.
  • Consistent Prefix: See initial sequence of writes.
  • Bounded Staleness: See all “old” writes.
  • Monotonic Reads: See increasing subset of writes.
  • Read My Writes: See all writes performed by reader.

I think my biggest takeaway is that its rather easy to reason about consistency levels for application semantics, and we should do it more often, at least as often as we think about our storage capacity and computing limits.