SAP-C02 Question 489
Select 2Your organization hosts a critical web application on AWS. The application is behind an Application Load Balancer (ALB) and uses Amazon EC2 instances in an Auto Scaling group across two Availability Zones. Recently, your application has experienced sudden spikes in traffic that cause temporary latency issues due to under-provisioned compute resources. Which combination of solutions would best address this issue while maintaining cost efficiency?
- A
Configure a target tracking scaling policy for the Auto Scaling group based on average CPU utilization.
- B
Enable ALB access logs to analyze traffic patterns and manually adjust the Auto Scaling group's minimum capacity.
- C
Pre-warm the Application Load Balancer to handle sudden traffic spikes.
- D
Set up a scheduled scaling policy in the Auto Scaling group based on known peak traffic times.
- E
Use EC2 Auto Scaling lifecycle hooks to delay scaling actions until the instances are fully ready to handle traffic.
Show answer and explanation
Correct answers: A, D
Explanation
To address sudden traffic spikes effectively, a combination of dynamic and proactive scaling is ideal. A target tracking scaling policy ensures that the Auto Scaling group can respond dynamically to changes in traffic, while a scheduled policy preemptively prepares for known traffic patterns. These methods work together to maintain application performance and cost efficiency. Other options, such as manually adjusting resources or pre-warming the ALB, are either inefficient or unnecessary in this scenario.
- A. Correct.
Target tracking scaling policies automatically adjust the number of instances in the Auto Scaling group based on metrics like CPU utilization. This ensures that the scaling actions respond dynamically to traffic spikes, improving performance without overprovisioning resources, making it both effective and cost-efficient.
- B. Incorrect.
While enabling ALB access logs can help analyze traffic patterns, manually adjusting the Auto Scaling group is not efficient for handling sudden, unpredictable spikes in traffic.
- C. Incorrect.
Pre-warming an Application Load Balancer is generally only needed for sudden and extremely high increases in traffic that the ALB cannot handle immediately. However, this is not applicable in most cases since ALBs can scale automatically to handle typical traffic bursts.
- D. Correct.
A scheduled scaling policy proactively scales instances during known peak times. This complements a target tracking scaling policy for predictable traffic patterns, ensuring sufficient capacity during traffic spikes while maintaining cost efficiency.
- E. Incorrect.
Lifecycle hooks delay the availability of instances until certain conditions are met, such as application initialization. While useful in some scenarios, they do not directly address the problem of under-provisioned resources during traffic spikes.