1.Aurora Architecture and Endpoints
An Aurora DB cluster separates compute from storage — one shared cluster volume spans multiple AZs, and every instance (the one writer, up to 15 readers) reads from that same volume rather than each holding its own copy. The cluster endpoint always points at the current writer; the reader endpoint load-balances across all readers and automatically re-points on failover.
Key features
- A cluster volume spans multiple AZs and is shared by every instance in the cluster — even a single-instance Aurora setup is still technically a cluster
- One primary (writer) instance handles all writes; up to 15 Aurora Replicas (readers) share the same storage and serve read-only queries
- Cluster endpoint: always the current writer — use for DDL/DML/general-purpose connections
- Reader endpoint: load-balances across all readers, automatically re-points if a reader is promoted during failover
- On primary failure, Aurora promotes an existing replica (or creates a new primary) — the cluster endpoint automatically follows
- Writer instance — cluster endpoint — all writes
- Reader instances (up to 15) — reader endpoint — load-balanced reads
- Shared cluster volume — spans multiple AZs, one copy of the data
Signature
Cluster endpoint (writer) · reader endpoint (readers) · shared cluster volume
Aurora separates compute from storage — one shared cluster volume across AZs, up to 15 readers sharing it with the one writer. Use the cluster endpoint (always the writer) and reader endpoint (load-balanced readers) — both automatically follow failover; instance endpoints do not.