ANS-C01 Question 86
Select 2You are designing a highly available application in AWS that serves users from multiple Availability Zones. The application requires consistent session management to ensure users are not logged out when their requests are routed to different backend instances. Additionally, the system needs to balance traffic efficiently across all backend instances, even if there are more instances in one Availability Zone than another. Which configuration options should you enable on your Application Load Balancer (ALB)?
- A
Enable cross-zone load balancing on the ALB
- B
Enable session affinity (sticky sessions) on the ALB
- C
Enable the proxy protocol version 2 on the ALB
- D
Use a round-robin routing algorithm on the ALB
- E
Configure the ALB to route traffic based on the source IP address
Show answer and explanation
Correct answers: A, B
Explanation
To meet the requirements of the scenario, enabling cross-zone load balancing ensures traffic is evenly distributed across backend instances in multiple Availability Zones, while enabling session affinity (sticky sessions) ensures that user sessions are consistently routed to the same backend instance. These two configurations together fulfill the application's need for high availability and consistent session management.
- A. Correct.
Cross-zone load balancing ensures that traffic is evenly distributed across all backend instances, regardless of the number of instances in each Availability Zone. This is necessary for efficient load balancing in a multi-AZ setup.
- B. Correct.
Session affinity (sticky sessions) ensures that user requests are consistently routed to the same backend instance, maintaining session continuity. This is required for consistent session management.
- C. Incorrect.
The proxy protocol version 2 is used to preserve client connection information, such as the source IP address, but it is not relevant for session management or balancing traffic across Availability Zones.
- D. Incorrect.
The round-robin routing algorithm is a default routing mechanism for distributing traffic but does not inherently address cross-zone balancing or session affinity requirements.
- E. Incorrect.
Routing traffic based on the source IP address is not relevant for session management or cross-zone load balancing in this scenario.