CSE 452: Distributed Systems

Lab 1 Design Doc

Intro

  • A design document describes a distributed protocol at a high-level but with enough detail that a competent programmer could implement it without having to think about any distributed systems-y aspects of the problem (a big ask!).
  • The act of taking high level ideas and turning them into concrete distributed protocols that can be implemented, evaluated, and deployed is a core skill that we hope you develop in this course!

Design Doc for Lab 1

  • You will write a design document for lab 1 part c (exactly once semantics).
  • Follow the template.
    • You can submit your design doc as any typeset PDF on Gradescope.
      • The text can be plain ascii, word doc, latex, or other. Diagrams can be in any readable form, including hand sketched.
    • Be sure these sections appear explicitly with exactly these titles in large font in your doc
      • Preface
      • Protocol
      • Correctness/Liveness Analysis
      • Conclusion
    • Besides those section titles, you do not have to follow the rest of the template exactly, but you must include the spirit of all the information requested in the template in some format.
    • Feel free to include diagrams or informal discussion wherever you see fit.
  • You should be specific about state, messages, timers.
  • Try to avoid low-level Java-specific details where possible. Your document should make sense in any programming language.

Advice

Here are some common tips and traps:

  • Do not repeat yourself. Do not copy paste. Instead, you can say "it is similar to blah", where "blah" directs the reader to the relevant part of the document.
  • Structure your design doc so that it is readable. When answering several questions from the template about a single variable, group all the answers about one variable together, do not group answers by question.
  • Try to keep your design doc concise. In particular, lab 1 is just a warmup.
  • The most important section is the protocol section. That is the section you will translate into Java. Be extremely specific about exactly what data each node stores, what data is on each message/timer, and how a node's state changes when a message/timer is delivered/fired. "Extremely specific" does not mean "long winded". Be precise but concise.