1 "Distributed-Systems" Post

The Birthday Paradox in Production: When Random IDs Collide

Why collision risk grows faster than intuition suggests, and what that means for IDs, hashes, and distributed systems
What You'll Learn
  • Why collisions happen long before an ID space is full
  • Why collision risk grows much faster than intuition suggests
  • How the birthday paradox applies to computer systems
  • How to calculate the probability of an ID collision
  • Why the square root of the ID space determines the danger zone
  • How 32-bit, 64-bit, and UUID v4 IDs compare
  • How generation rate changes the time until collisions become likely
  • How to choose an acceptable collision risk for a real system
  • How Monte Carlo simulation can validate collision calculations
  • How to predict when an ID strategy needs to be replaced