Asynchronous Replication
Summary: A replication strategy where the leader accepts writes and returns success to the client without waiting for responses from followers.
Sources: chapter5
Last updated: 2026-04-18
In asynchronous replication, the leader sends updates to followers but doesn’t wait for an acknowledgment. This allows the system to remain available for writes even if followers are lagging or disconnected.
Benefits and Drawbacks
- Performance: Very low latency for writes, as the leader doesn’t wait for network round-trips to replicas.
- Availability: The system can continue to accept writes as long as the leader is up.
- Durability Risk: If the leader fails before updates have reached followers, those writes may be lost (source: chapter5, p. 154).
- Consistency: Leads to eventual-consistency, as there is a replication-lag between the leader and followers.
Use Cases
Most widely used in systems where low latency and high availability are more important than strict consistency guarantees (e.g., social media feeds, logging).