What it is: Read-only instances in an Aurora cluster that replicate from the writer (primary).

What it’s for:

• Scale read traffic (read-heavy workloads).
• Improve availability (replicas can be promoted during failover).

Key ideas:

• Applications can use a reader endpoint to spread reads across replicas.
• During failover, a replica can be promoted to become the writer.

Exam cues:

• “read scaling for Aurora” → Aurora Replicas + reader endpoint.
• “improve availability with replicas” → Aurora replicas (promotion on failover).

Hard words:

• *read-only* /ˌriːd ˈoʊnli/: chỉ đọc
• *replicate* /ˈreplɪkeɪt/: sao chép
• *promoted* /prəˈmoʊtɪd/: được nâng lên
• *failover* /ˈfeɪlˌoʊvər/: chuyển dự phòng