A company runs an RDS MySQL database. They need automatic failover with minimal downtime if the primary database AZ fails. Which RDS feature should be enabled?
- ARDS Read Replicas — create asynchronous read-only copies for scaling reads.
- BRDS Multi-AZ Deployment — synchronous standby in another AZ with automatic failover.✓ Correct
- CRDS Automated Backups — daily snapshots and transaction logs for point-in-time recovery.
- DRDS Performance Insights — monitors database load and query performance.
RDS Multi-AZ maintains a synchronous standby replica in a different AZ. If the primary fails, RDS automatically promotes the standby (typically 60–120 seconds). Read Replicas use asynchronous replication and do NOT provide automatic failover — they are for read scaling only. Automated backups support PITR but cannot provide automatic failover.
A company's RDS PostgreSQL instance is overwhelmed by read queries from a reporting application. The primary instance must not be impacted. What is the BEST solution?
- AEnable RDS Multi-AZ — the standby can serve read traffic.
- BCreate one or more RDS Read Replicas and point the reporting application to the Read Replica endpoint.✓ Correct
- CIncrease the primary instance size to handle more concurrent queries.
- DEnable automated backups — this reduces load by offloading backup I/O.
RDS Read Replicas use asynchronous replication to maintain one or more read-only copies of the primary. You can direct read-heavy applications (reporting, analytics) to these replicas, reducing load on the primary. The Multi-AZ standby is NOT used for read traffic — it is only for failover purposes.
What is the maximum retention period for RDS automated backups?
- A7 days (the default retention period).
- B14 days.
- C35 days.✓ Correct
- D90 days.
RDS automated backups can be retained for 0 to 35 days. The default is 7 days. Setting retention to 0 disables automated backups. For longer retention, you must use manual DB snapshots, which are kept until you explicitly delete them. Aurora supports backup retention of up to 35 days as well.
A company uses AWS Lambda functions that create many short-lived database connections to RDS, causing connection exhaustion. What is the BEST solution?
- AIncrease the max_connections parameter on the RDS instance.
- BEnable RDS Proxy — it pools and shares database connections, reducing connection overhead from Lambda.✓ Correct
- CEnable RDS Multi-AZ to distribute connections across primary and standby.
- DMove the database to DynamoDB to avoid connection limits.
RDS Proxy maintains a pool of established database connections and multiplexes many application connections onto fewer database connections. This is specifically designed for serverless architectures (Lambda) and microservices that open/close connections rapidly. It improves database efficiency and application resilience during failover.
A company runs a global application and needs sub-second Aurora MySQL replication across multiple AWS regions for low-latency local reads and cross-region DR. Which Aurora feature provides this?
- AAurora Read Replicas — limited to within the same region.
- BAurora Multi-AZ — provides HA within a single region only.
- CAurora Global Database — replicates data across up to 5 secondary regions with under 1 second replication lag.✓ Correct
- DAurora Serverless — automatically scales capacity but does not provide cross-region replication.
Aurora Global Database uses dedicated replication infrastructure to achieve typical replication lag of less than 1 second across regions. The primary region handles reads and writes; secondary regions handle reads and can be promoted to a primary within 1 minute for DR. It supports up to 5 secondary regions.