Definition

Geo-replication is replicating data across geographically distributed data centers.

Core concept

Ensures data is available near where it’s needed globally and provides disaster recovery. Usually asynchronous to tolerate high latencies, leading to eventual consistency across regions.

Use cases

Cloud storage (S3 cross-region), globally distributed databases (Cassandra in multi-DC mode, CockroachDB).

Trade-offs

Increased latency for cross-region sync, potential staleness. But improves read locality and resilience.

References

Networking and cloud best practices.