Quick Answer
The correct choice is to use pre-warming instances with a scheduled scaling rule. This approach directly addresses the cold start problem because reactive autoscaling, which triggers based on CPU percentage, suffers from a provisioning delay—new instances take time to initialize their runtime, load dependencies, and become responsive. By scheduling pre-warmed instances to spin up ahead of known traffic spikes, you ensure that capacity is already online and ready, eliminating the lag that causes unresponsiveness during rapid load increases. On the AZ-204 exam, this scenario tests your understanding of the difference between reactive and proactive scaling strategies; a common trap is to assume that simply lowering the CPU threshold or increasing the autoscale instance count will solve the delay, but those options still rely on a reactive trigger. Remember the memory tip: "Pre-warm before the storm"—schedule your scaling to anticipate demand, not react to it.
This AZ-204 practice question tests your understanding of develop azure compute solutions. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A company runs a critical web app on Azure App Service that must handle traffic spikes without downtime. They set up autoscaling rules based on CPU percentage. However, during a spike, the app becomes unresponsive before new instances are added. What should they do?
Switch to memory-based autoscaling
Why wrong: Memory might not be the bottleneck; CPU is the issue.
Decrease the scale-in cooldown period
Why wrong: Scale-in reduces instances, not helpful for spikes.
Use pre-warming instances with a scheduled scaling rule
Pre-warming ensures instances are ready before the spike.
Increase the CPU percentage threshold for scale-out
Why wrong: This would delay scaling, making the problem worse.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
Use pre-warming instances with a scheduled scaling rule
Option C is correct because pre-warming instances with a scheduled scaling rule ensures that additional instances are already running and ready to handle traffic before the CPU spike occurs. This avoids the cold-start delay inherent in reactive autoscaling, where new instances take time to provision and initialize, causing unresponsiveness during rapid spikes.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
Switch to memory-based autoscaling
Why it's wrong here
Memory might not be the bottleneck; CPU is the issue.
Decrease the scale-in cooldown period
Why it's wrong here
Scale-in reduces instances, not helpful for spikes.
Use pre-warming instances with a scheduled scaling rule
Why this is correct
Pre-warming ensures instances are ready before the spike.
Related concept
Read the scenario before looking for a memorised answer.
Increase the CPU percentage threshold for scale-out
Why it's wrong here
This would delay scaling, making the problem worse.
Common exam traps
The trap here is that candidates assume reactive autoscaling (e.g., lowering thresholds or changing metrics) can solve latency issues, but they overlook the fundamental cold-start delay that requires proactive instance pre-warming.
Detailed technical explanation
Azure App Service autoscaling uses metrics like CPU percentage to trigger scale-out operations, but new instances require time for provisioning, application initialization, and health checks (often 30-90 seconds). Scheduled pre-warming rules bypass this latency by ensuring instances are already running and registered with the load balancer before the spike, leveraging Azure's 'Always On' and warm-up request features to minimize cold-start impact.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
An e-commerce site experiences heavy traffic on Black Friday and near-zero traffic during off-peak weeks. Rather than provisioning permanent large VMs, the team uses auto-scaling groups that add capacity automatically under load and reduce it overnight. Questions like this test whether you understand elasticity, availability zones, and cloud compute scaling patterns.
What to study next
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Develop Azure compute solutions — study guide chapter
Learn the concepts, then practise the questions
Develop Azure compute solutions practice questions
Targeted practice on this topic area only
All AZ-204 questions
997 questions across all exam domains
Microsoft Azure Developer Associate AZ-204 study guide
Full concept coverage aligned to exam objectives
AZ-204 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Practise AZ-204 questions linked to Develop Azure compute solutions.
Practise AZ-204 questions linked to Develop for Azure storage.
Practise AZ-204 questions linked to Implement Azure security.
Practise AZ-204 questions linked to Connect to and consume Azure services and third-party services.
Practise AZ-204 questions linked to Monitor, troubleshoot, and optimize Azure solutions.
Practise AZ-204 questions linked to AZ-204 fundamentals.
Practise AZ-204 questions linked to AZ-204 scenario.
Practise AZ-204 questions linked to AZ-204 troubleshooting.
Practice this exam
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Develop Azure compute solutions — This question tests Develop Azure compute solutions — Read the scenario before looking for a memorised answer..
The correct answer is: Use pre-warming instances with a scheduled scaling rule — Option C is correct because pre-warming instances with a scheduled scaling rule ensures that additional instances are already running and ready to handle traffic before the CPU spike occurs. This avoids the cold-start delay inherent in reactive autoscaling, where new instances take time to provision and initialize, causing unresponsiveness during rapid spikes.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Last reviewed: Jun 24, 2026
This AZ-204 practice question is part of Courseiva's free Microsoft certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the AZ-204 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.