Horizontal scaling.
also: scale out · scaling out · scale horizontallyAdding more machines and spreading the load across them, instead of making one machine bigger.
the two-minute refresher
- Add servers behind a load balancer; capacity grows roughly linearly.
- No hard ceiling, and one machine dying is no longer an outage.
- Needs stateless services, and data sharding or replication for databases.
- Costs complexity: distributed coordination, consistency and more moving parts.