How to Proactively Scale an Auto Scaling Group for an Annual Holiday Peak
Short answer
B Create a recurring scheduled action to scale up the Auto Scaling group before the expected period of peak demand.
Question
Key Takeaways
It tests the difference between proactive and reactive Auto Scaling; the trap is choosing CPU-based dynamic scaling, which only reacts after users already feel performance degradation.
This SAA-C03 question asks how to proactively add EC2 capacity before a predictable annual holiday traffic spike. The answer is a recurring scheduled action (B), which scales the Auto Scaling group out ahead of the known peak instead of waiting for a reactive CloudWatch alarm.
Common mistake: Many candidates choose A, a CloudWatch CPU alarm, because it sounds operationally sound, but dynamic scaling triggers only after load is already high, so it cannot satisfy the requirement to minimize performance impact proactively.
Expert Analysis
Why the Answer Is Correct
A recurring scheduled action is the only option that increases capacity before the known holiday demand arrives. EC2 Auto Scaling scheduled actions let you specify a future date/time and the desired capacity, so the group can scale out proactively. Because the application history shows the spike happens every year during a holiday, the timing is predictable and does not need to be inferred from metrics. This directly satisfies the requirement to minimize performance impact on application users. Option B therefore matches both the proactive wording and the recurring nature of the event.
Why the Other Options Are Wrong
A creates a CloudWatch alarm that scales up only after CPU utilization exceeds 90%, which is reactive and therefore too late to prevent user impact. C increases the minimum and maximum instance counts during the peak period, but that is a manual limit change rather than an automatic pre-peak scale-out, and it does not by itself add capacity at the right time. D configures an SNS notification for instance launch events, which only informs operators and does not scale the Auto Scaling group at all. None of these options proactively increases capacity based on the anticipated holiday schedule.
Community Comment Notes
KennethNg923 captured the trigger phrase, quoting that "the company anticipates a spike in traffic during a holiday each year". Mikado211 agreed that scheduled scaling fits because "Since we know when we will have a peak of activity. A scheduled scaling is a good idea." Scheldon pointed to a proactive-vs-reactive scaling article, reinforcing that scheduled scaling is the proactive choice. 7ce90e0 summed up the deciding keyword: "it says proactively." Cpso preferred C, but that changes the group's limits rather than scheduling an automatic pre-peak scale-out; Hkayne's bare claim for A does not overcome the reactive nature of CPU alarms.
Official Reference
https://docs.aws.amazon.com/autoscaling/ec2/userguide/ec2-auto-scaling-scheduled-scaling.html
This link opens the official vendor documentation in a new tab.
Exam Strategy
Look for schedule words such as yearly, holiday, or anticipated peak; they point to scheduled scaling rather than dynamic scaling. If the question instead says unknown or unpredictable traffic, then target tracking or step scaling becomes the better fit.
Frequently Asked Questions
Why is a CloudWatch CPU alarm not proactive enough for the holiday spike?
Does raising the Auto Scaling group's maximum size automatically add capacity before the peak?
Community Votes
100% of anonymous learners picked answer B. Votes are pick records left by other test-takers — they are not the verified answer.
Discussion 7 contributions
Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.
From public community threads 7
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Scheldon 👍 4 Answered BAnswerB https://medium.com/@damadhav/aws-scaling-reactive-vs-proactive-vs-predictive-2701ad6d48c9
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KennethNg923 👍 3 Answered Bthe company anticipates a spike in traffic during a holiday each year -> schedule action
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Mikado211 👍 3 Answered BSince we know when we will have a peak of activity. A scheduled scaling is a good idea.
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zinabu 👍 2 Answered Bit needs a scheduled action for the yearly holiday peak traffic
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Cpso 👍 1 Answered Cobjective is to optimize autoscaling but being fix number of ec2: "design a strategy to ensure that the Auto Scaling group proactively increases capacity to minimize any performance impact on application users."
Show 2 more comments
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7ce90e0 👍 4 Answered Bit says proactively
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Hkayne 👍 1 Answered AThe answer IS A
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