The answer is that the CloudWatch agent is not installed or configured to collect memory metrics. This is the most likely cause of the missing alarms because, by default, the standard CloudWatch metrics for EC2 instances only include CPU utilization, disk I/O, and network traffic—memory usage is not collected without the unified CloudWatch agent. The agent must be explicitly installed and configured with a JSON file to gather custom metrics like memory and disk swap, and if it is missing, alarms for memory usage will never trigger even when the system runs out of memory. On the AWS Certified DevOps Engineer Professional DOP-C02 exam, this scenario tests your understanding of the difference between basic monitoring and detailed monitoring with the CloudWatch agent, a common trap where engineers assume memory metrics are automatically available. A useful memory tip: "Default metrics are CPU-centric; memory needs an agent."
DOP-C02 Incident and Event Response Practice Question
This DOP-C02 practice question tests your understanding of incident and event response. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. 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 DevOps engineer notices that an EC2 instance running a critical application is unresponsive. CloudWatch alarms for CPU utilization and memory usage did not trigger. The engineer checks the system logs and finds an 'Out of memory: Kill process' error. What is the MOST likely cause of the missed alarms?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The CloudWatch agent is not installed or configured to collect memory metrics.
Option D is correct because the CloudWatch agent must be configured to collect memory metrics; CPU metrics are collected by default. Option A is wrong because instance store volumes would not affect CloudWatch metrics. Option B is wrong because CloudWatch metrics are stored for 15 months. Option C is wrong because the root volume size does not prevent metric collection.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✓
The CloudWatch agent is not installed or configured to collect memory metrics.
Why this is correct
Memory metrics require the CloudWatch agent; default monitoring only collects CPU, disk, and network.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
The instance is using instance store volumes instead of EBS, which prevents metric collection.
Why it's wrong here
Instance store volumes do not prevent CloudWatch metric collection.
✗
The CloudWatch metrics retention period is set to 1 day, so old alarms were deleted.
Why it's wrong here
Retention period does not affect alarm triggering.
✗
The EC2 instance's root EBS volume is encrypted, blocking CloudWatch agent logs.
Why it's wrong here
EBS encryption does not block CloudWatch agent.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.
Detailed technical explanation
How to think about this question
This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
Use explanations to understand the rule behind the answer.
TExam Day Tips
→Underline the problem statement mentally.
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A cloud solutions architect for a retail company is evaluating services for a new workload. The correct answer here reflects best practice for the specific scenario described — not a general cloud recommendation. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Cloud exam questions reward reading the constraint carefully: the same technology can be right or wrong depending on the use case.
What to study next
Got this wrong? Here's your next step.
Identify which DOP-C02 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
Incident and Event Response — This question tests Incident and Event Response — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The CloudWatch agent is not installed or configured to collect memory metrics. — Option D is correct because the CloudWatch agent must be configured to collect memory metrics; CPU metrics are collected by default. Option A is wrong because instance store volumes would not affect CloudWatch metrics. Option B is wrong because CloudWatch metrics are stored for 15 months. Option C is wrong because the root volume size does not prevent metric collection.
What should I do if I get this DOP-C02 question wrong?
Identify which DOP-C02 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
What is the key concept behind this question?
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 →
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.
This DOP-C02 practice question is part of Courseiva's free Amazon Web Services 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 DOP-C02 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.