Virtual nodes.
also: virtual node · vnodes · vnodePlacing each physical node at many points on the hash ring, so keys spread evenly and a removed node's load spreads widely.
the two-minute refresher
- With one point per node, arcs are uneven and one node can own far more keys.
- Hundreds of virtual nodes per server make the distribution statistically even.
- When a node leaves, its arcs go to many neighbours, not one.
- They are about balance, not replication; lookups are still a binary search over the ring.