Distributed
← Core building blocks

Lesson 01.3

Consistent hashing & virtual nodes

Consistent hashing assigns keys to positions on a ring so membership changes affect a limited set of owners. Virtual nodes give each physical server multiple positions to improve balance.

Add a computer without rearranging everything

Ava and Ben use three computers to remember cookie orders. They add a fourth computer to help. A rule based on dividing by the number of computers suddenly sends many old orders somewhere else.

In this lesson you'll

  1. 1Follow one run and learn how to read the picture
  2. 2Predict what changes before revealing the result
  3. 3Move D past 70% of the circle without disturbing unrelated owners