- Replication means copying data across multiple servers or nodes.
- Improves availability by allowing reads/writes from multiple copies.
- If one node fails, others can serve requests.
- Common replication types:
- Master-Slave: One master handles writes; slaves handle reads.
- Master-Master: Multiple masters handle reads and writes, sync data between them.
- Helps reduce latency by serving data from the nearest replica.
- Must handle data consistency between replicas (can lead to eventual consistency).
- Enables fault tolerance and load balancing.