Replication
The maintenance of multiple copies of data or state across nodes to improve availability, locality, durability, or read scalability.
Distributed-Systems Context
Replication keeps multiple copies of data or state to improve availability, locality, durability, or read capacity. Leader-follower, multi-leader, and leaderless designs make different trade-offs in consistency, conflict resolution, write availability, and operational complexity.
Durability Boundary
Replication is not a backup. A user mistake, bad deployment, or logical corruption can be propagated to every replica, while replication lag can create stale reads and a window of data loss during failover.
Related Distributed-Systems Concepts
- Quorum
- Leader Election
- Replication Lag
- Consistency