- A
The firewall rule allowing traffic from web-01 to db-01 on port 3306 has been removed or misconfigured.
The timeout when connecting to the database suggests a firewall or network path issue blocking TCP/3306 traffic.
- B
The database instance db-01 is running out of memory and rejecting connections.
Why wrong: Timeout suggests network-level issue, not resource exhaustion (which would typically produce a different error).
- C
The load balancer health check is misconfigured to use an incorrect port.
Why wrong: The health check failure is a symptom, not the root cause; the underlying issue is the database connectivity.
- D
The instance web-01 is running an outdated version of the web server software.
Why wrong: There is no evidence of outdated software; the logs point to a connectivity issue.
Google PCA Design and plan a cloud solution architecture Practice Question
This PCA practice question tests your understanding of design and plan a cloud solution architecture. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. 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.
Refer to the exhibit. An engineer is investigating why web-01 was removed from the load balancer target pool. What is the most likely root cause?
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 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
The firewall rule allowing traffic from web-01 to db-01 on port 3306 has been removed or misconfigured.
The error logs show that web-01 cannot connect to the database (10.128.0.5) due to timeout. This indicates a network connectivity issue between web-01 and db-01, which likely caused the health check to fail, leading to removal from the target pool.
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 firewall rule allowing traffic from web-01 to db-01 on port 3306 has been removed or misconfigured.
- ✗
The database instance db-01 is running out of memory and rejecting connections.
Why it's wrong here
Timeout suggests network-level issue, not resource exhaustion (which would typically produce a different error).
- ✗
The load balancer health check is misconfigured to use an incorrect port.
Why it's wrong here
The health check failure is a symptom, not the root cause; the underlying issue is the database connectivity.
- ✗
The instance web-01 is running an outdated version of the web server software.
Why it's wrong here
There is no evidence of outdated software; the logs point to a connectivity issue.
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 healthcare organisation deploys an application with a public-facing web tier and a private database tier. The database subnet has no public IP and only accepts connections from the web tier's security group. Questions like this test whether you can design cloud network isolation using VNets/VPCs, subnets, and security group rules.
What to study next
Got this wrong? Here's your next step.
Identify which PCA 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.
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FAQ
Questions learners often ask
What does this PCA question test?
Design and plan a cloud solution architecture — This question tests Design and plan a cloud solution architecture — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The firewall rule allowing traffic from web-01 to db-01 on port 3306 has been removed or misconfigured. — The error logs show that web-01 cannot connect to the database (10.128.0.5) due to timeout. This indicates a network connectivity issue between web-01 and db-01, which likely caused the health check to fail, leading to removal from the target pool.
What should I do if I get this PCA question wrong?
Identify which PCA 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 →
Last reviewed: Jul 4, 2026
This PCA practice question is part of Courseiva's free Google Cloud 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 PCA exam.
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