SAP-C02 Question 518
Select 2Your company is running a multi-region application that uses Amazon RDS for its primary database. The database is set up in the us-east-1 region, and you have enabled cross-region read replicas in the us-west-2 region to improve read performance. You have recently discovered that the cross-region read replica is lagging significantly behind the primary database. Which of the following actions should you take to minimize the replication lag?
- A
Enable Multi-AZ deployment for the primary database in us-east-1.
- B
Ensure the cross-region replication uses encrypted connections.
- C
Use an Amazon RDS read replica closer to the primary database, such as in another Availability Zone within the same region.
- D
Switch from asynchronous replication to synchronous replication between the primary database and the read replica.
- E
Upgrade the instance class of the read replica to a more powerful instance type.
Show answer and explanation
Correct answers: C, E
Explanation
Replication lag in RDS read replicas can be influenced by factors such as network latency and the processing capacity of the read replica. Deploying the read replica closer to the primary database (e.g., in another Availability Zone within the same region) minimizes network latency. Additionally, upgrading the read replica's instance class improves its processing capacity to handle replication logs more efficiently. Other options, such as enabling Multi-AZ or using encrypted connections, are unrelated to addressing replication lag.
- A. Incorrect.
Enabling Multi-AZ deployment improves high availability and failover for the primary database but does not directly address cross-region replication lag.
- B. Incorrect.
Encryption of connections improves security but has no significant effect on replication performance or lag.
- C. Correct.
Using a read replica in the same region, in another Availability Zone, reduces the latency between the primary database and the replica, thereby minimizing replication lag.
- D. Incorrect.
RDS cross-region replication uses asynchronous replication by design, and switching to synchronous replication is not supported in this scenario.
- E. Correct.
Upgrading the instance class of the read replica provides more resources, such as CPU and memory, for processing replication logs, which can help reduce lag.