Scaling

Virtual Nodes

Placing each physical node at many ring positions (typically 100–200) so arcs are even.

Why interviewers ask about it

Without them, three nodes on three random positions can split 60/20/20. They also spread a removed node's keys across all survivors.

Map keys and nodes onto a ring; a key belongs to the first node clockwise. Adding a node moves only ~1/N of keys.

This term is part of the free System Design interview preparation module - browse the full glossary for every definition.