How is data replication carried out in distributed systems?

Data replication in distributed systems is the process of copying and maintaining up-to-date copies of data on multiple nodes to improve availability and fault tolerance.

Main approaches:

• Synchronous replication: data is written simultaneously to all replicas. Ensures consistency but may reduce performance due to delays.
• Asynchronous replication: data is first written to the primary node, then copied to replicas with delay. Improves performance but may have temporary inconsistency.

The process typically involves:

1. Designating a master node that accepts writes.
2. Propagating changes to secondary nodes.
3. Confirming successful replication.
4. Handling conflicts and recovery after failures.

In Go, channels and goroutines are often used for asynchronous data transfer between nodes.