DOP-C02 Question 196
Select 3An e-commerce company runs a highly available, multi-region application on AWS. To ensure disaster recovery in case of a regional failure, the company has set up a pilot light environment in a secondary region. During a recent disaster recovery drill, it was observed that the failover time to the secondary region is longer than expected. What steps can you take to reduce the failover time while still maintaining the pilot light strategy?
- A
Pre-warm the Amazon RDS read replica in the secondary region by upgrading it to a larger instance class.
- B
Replicate the application servers in the secondary region and keep them running with minimal capacity.
- C
Use AWS Lambda to automatically scale up the secondary region resources during a failover event.
- D
Pre-configure Route 53 health checks and DNS failover policies to redirect traffic to the secondary region.
- E
Enable cross-region replication for the Amazon S3 buckets used by the application.
Show answer and explanation
Correct answers: B, D, E
Explanation
The pilot light strategy involves maintaining a minimal version of the production environment in the secondary region to reduce costs while being prepared for disaster recovery. To reduce failover time, it's important to pre-configure critical components such as application servers, DNS failover policies, and data replication (e.g., Amazon S3 cross-region replication). This ensures that the secondary region can take over with minimal delay during a disaster.
- A. Incorrect.
Pre-warming the Amazon RDS read replica by upgrading it to a larger instance class is not a recommended step for reducing failover time in a pilot light strategy. The focus should be on activating the resources quickly during failover, not necessarily resizing them upfront.
- B. Correct.
Replicating the application servers in the secondary region and keeping them running with minimal capacity aligns well with the pilot light strategy. This setup ensures core functionality is pre-configured and can be scaled quickly during failover.
- C. Incorrect.
Using AWS Lambda to scale up secondary region resources during a failover is not directly applicable to pilot light. While automation can help, the pilot light strategy focuses on having pre-provisioned but minimal resources in the secondary region.
- D. Correct.
Pre-configuring Route 53 health checks and DNS failover policies ensures faster redirection of traffic to the secondary region during failover, reducing the overall downtime.
- E. Correct.
Enabling cross-region replication for Amazon S3 buckets ensures that the data is already synchronized in the secondary region, reducing the time needed to restore data during failover.