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Nobody Knows What Time It Is

Vaidehi Joshi
April 27, 2018

Nobody Knows What Time It Is

Someone once said that time is a flat circle, which is all well and good...but how on earth does anyone know what time it actually is? In this talk, we’ll try to understand why time is such a hard problem in distributed systems, some of the ways that people have tried to solve this problem, and how one computer scientist's solution completely changed the trajectory of the internet forever.

Vaidehi Joshi

April 27, 2018


  1. @vaidehijoshi “When I looked at the algorithm, I realized that

    it wasn’t quite right. It permitted a system to do things that, in ways, seemed to violate causality. — Leslie Lamport
  2. @vaidehijoshi p a q b r d c e g

    h f a → d → e a → b→ g → h
  3. @vaidehijoshi when receiving events, a process chooses the greater of

    the two counters, and increments it by 1 to acknowledge the receive event