Consistent Hashing

Summary

A hashing technique that minimizes data redistribution when nodes are added or removed from a distributed cache or database cluster — instead of remapping almost everything on every change.

• 1Read a visual explanation of consistent hashing — the 'hash ring' concept.
• 2Compare it to naive modulo hashing and see why the latter causes massive remapping on a resize.
• 3Recognize this concept in tools you may already use, like memcached client libraries.