SOA-C02 Question 82
Select 3An e-commerce company has deployed a web application behind an Elastic Load Balancer (ELB). To ensure high availability and fault tolerance, the company uses Amazon Route 53 to route traffic to the ELB. The company also wants Route 53 to avoid routing traffic to the ELB if all its backend instances are unhealthy. What steps should the SysOps Administrator take to meet this requirement?
- A
Configure health checks on the ELB to monitor the health of backend instances.
- B
Create an HTTP health check in Route 53 that points to the ELB’s public DNS.
- C
Configure a Route 53 health check that evaluates the ELB health check status.
- D
Set the 'Evaluate Target Health' option to 'Yes' in the Route 53 record pointing to the ELB.
- E
Disable health checks on the ELB since health checks will now be managed by Route 53.
Show answer and explanation
Correct answers: A, C, D
Explanation
To ensure Route 53 routes traffic only to healthy endpoints, the ELB must be configured with health checks to monitor the backend instances. Additionally, Route 53 can evaluate the health status of the ELB via a health check or by enabling the 'Evaluate Target Health' option in the Route 53 record. Together, these configurations ensure high availability and fault tolerance.
- A. Correct.
Correct. The ELB must be configured with health checks to monitor the health of backend instances. This ensures that unhealthy instances are removed from the load balancer’s pool.
- B. Incorrect.
Incorrect. Route 53 does not directly perform health checks against the ELB’s public DNS. Instead, it evaluates the ELB's health checks.
- C. Correct.
Correct. A Route 53 health check can use the ELB's health check status to determine whether traffic should be routed to the ELB.
- D. Correct.
Correct. Setting 'Evaluate Target Health' to 'Yes' ensures that Route 53 takes into account the health status of the ELB when routing traffic.
- E. Incorrect.
Incorrect. Disabling ELB health checks is not recommended since the ELB must monitor the health of backend instances to function properly.