PAS-C01 CloudWatch cross-account observability Practice Question
A company wants to centralize monitoring of EC2 instance metrics across multiple AWS accounts. Which solution is MOST scalable and cost-effective?
⚠ Common exam trap
Candidates may confuse cross-region metrics (option B) with cross-account observability, or overcomplicate the solution with S3 and Athena (option C). The key is to recognize that cross-account observability is purpose-built for this scenario.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Set up CloudWatch cross-account observability with a monitoring account.
CloudWatch cross-account observability (option D) is the most scalable and cost-effective solution for centralizing monitoring across multiple AWS accounts, as it allows a single monitoring account to aggregate metrics, logs, and traces from source accounts without manual logins or complex data pipelines. Option A, while not scalable for large environments, can be used for simple, ad-hoc checks in small setups; however, the question specifically asks for the MOST scalable and cost-effective approach, which is solely option D. The previous marking of option B as correct was in error; option B refers to cross-region metrics, which do not aggregate across accounts. Option C is inefficient and costly due to storage and query overhead.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Log in to each account and view CloudWatch metrics individually.
Why it's wrong here
This requires manual logins and is not scalable; it is not the most scalable or cost-effective solution.
- ✗
Use CloudWatch cross-region metrics to aggregate metrics in a single account.
Why it's wrong here
Cross-region metrics aggregate across regions but not accounts, so this does not solve the cross-account requirement.
- ✗
Configure each account to publish metrics to an S3 bucket and use Athena to query.
Why it's wrong here
Publishing to S3 and using Athena introduces unnecessary complexity and cost compared to the native cross-account feature.
- ✓
Set up CloudWatch cross-account observability with a monitoring account.
Why this is correct
CloudWatch cross-account observability natively centralizes monitoring from multiple accounts into a single monitoring account, making it both scalable and cost-effective.
Quick reference
AWS S3 Storage Class Comparison
| Storage Class | Min Duration | Retrieval | Use Case |
|---|---|---|---|
| S3 Standard | None | Immediate | Frequently accessed data |
| S3 Standard-IA | 30 days | Immediate | Infrequent access, rapid retrieval |
| S3 One Zone-IA | 30 days | Immediate | Non-critical infrequent data |
| S3 Intelligent-Tiering | None | Immediate–hours | Unknown or changing access patterns |
| S3 Glacier Instant | 90 days | Milliseconds | Archive with instant retrieval |
| S3 Glacier Flexible | 90 days | Minutes–hours | Archive, flexible retrieval |
| S3 Glacier Deep Archive | 180 days | Hours | Long-term compliance archive |
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This PAS-C01 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 PAS-C01 exam.