- A
The container was deployed from source and Cloud Run requires a pre-built image.
Why wrong: Incorrect. Cloud Run supports deploying from source using buildpacks; a pre-built image is not required.
- B
The container is listening on port 3000 instead of the port Cloud Run expects.
Correct. The container must listen on the port specified by the PORT environment variable (default 8080). Listening on port 3000 causes Cloud Run to fail routing traffic.
- C
The service requires authentication but --allow-unauthenticated was not set.
Why wrong: Incorrect. Authentication settings affect access control, not traffic routing. The service can still receive traffic even if authentication is required, but requests from unauthenticated users will be rejected.
- D
The container does not support concurrent requests.
Why wrong: Incorrect. Even if a container does not support concurrent requests (i.e., it can only handle one request at a time), Cloud Run will still route traffic to it, just with limited concurrency.
Google ACE PORT environment variable Practice Question
This ACE practice question tests your understanding of deploying and implementing a cloud solution. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. A key principle to apply: pORT environment variable. 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.
An engineer deployed a container to Cloud Run but the service is not receiving traffic. The engineer checks the logs and finds no errors. The container listens on port 8080. What is the most likely cause of the issue?
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 container is listening on port 3000 instead of the port Cloud Run expects.
Cloud Run injects a PORT environment variable (default 8080) and expects the container to listen on that port. If the container listens on a different port, such as 3000, Cloud Run will not route traffic to it. Option A is incorrect because Cloud Run supports deploying from source using buildpacks. Option C is incorrect because authentication settings do not affect traffic routing; they control access. Option D is incorrect because Cloud Run can handle concurrent requests, but a container that doesn't support concurrency will still receive traffic, just one at a time. Therefore, the most likely cause is a port mismatch.
Key principle: PORT environment variable
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 container was deployed from source and Cloud Run requires a pre-built image.
Why it's wrong here
Incorrect. Cloud Run supports deploying from source using buildpacks; a pre-built image is not required.
- ✓
The container is listening on port 3000 instead of the port Cloud Run expects.
Why this is correct
Correct. The container must listen on the port specified by the PORT environment variable (default 8080). Listening on port 3000 causes Cloud Run to fail routing traffic.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
PORT environment variable
- ✗
The service requires authentication but --allow-unauthenticated was not set.
Why it's wrong here
Incorrect. Authentication settings affect access control, not traffic routing. The service can still receive traffic even if authentication is required, but requests from unauthenticated users will be rejected.
- ✗
The container does not support concurrent requests.
Why it's wrong here
Incorrect. Even if a container does not support concurrent requests (i.e., it can only handle one request at a time), Cloud Run will still route traffic to it, just with limited concurrency.
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
Treat this as a scenario question. Identify the problem, the constraint, and the best action. Then compare each option against those facts.
KKey Concepts to Remember
- PORT environment variable
- Cloud Run deployment from source
- Authentication and traffic routing
TExam Day Tips
- 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
PORT environment variable
Real-world example
How this comes up in practice
A company's IT admin needs to give a contractor read-only access to production logs without sharing account credentials. Using role-based access control (RBAC) and temporary scoped permissions — not a permanent shared password — is the correct pattern. Questions like this test whether you can apply least-privilege access across cloud identity services.
What to study next
Got this wrong? Here's your next step.
Review pORT environment variable, then practise related ACE questions on the same topic to reinforce the concept.
- →
Deploying and Implementing a Cloud Solution — study guide chapter
Learn the concepts, then practise the questions
- →
Deploying and Implementing a Cloud Solution practice questions
Targeted practice on this topic area only
- →
All ACE questions
1,000 questions across all exam domains
- →
Google Associate Cloud Engineer study guide
Full concept coverage aligned to exam objectives
- →
ACE practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related ACE practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Configuring Access and Security practice questions
Practise ACE questions linked to Configuring Access and Security.
Planning and Configuring a Cloud Solution practice questions
Practise ACE questions linked to Planning and Configuring a Cloud Solution.
Ensuring Successful Operation of a Cloud Solution practice questions
Practise ACE questions linked to Ensuring Successful Operation of a Cloud Solution.
Deploying and Implementing a Cloud Solution practice questions
Practise ACE questions linked to Deploying and Implementing a Cloud Solution.
Setting Up a Cloud Solution Environment practice questions
Practise ACE questions linked to Setting Up a Cloud Solution Environment.
ACE fundamentals practice questions
Practise ACE questions linked to ACE fundamentals.
ACE scenario practice questions
Practise ACE questions linked to ACE scenario.
ACE troubleshooting practice questions
Practise ACE questions linked to ACE troubleshooting.
Practice this exam
Start a free ACE practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this ACE question test?
Deploying and Implementing a Cloud Solution — This question tests Deploying and Implementing a Cloud Solution — PORT environment variable.
What is the correct answer to this question?
The correct answer is: The container is listening on port 3000 instead of the port Cloud Run expects. — Cloud Run injects a PORT environment variable (default 8080) and expects the container to listen on that port. If the container listens on a different port, such as 3000, Cloud Run will not route traffic to it. Option A is incorrect because Cloud Run supports deploying from source using buildpacks. Option C is incorrect because authentication settings do not affect traffic routing; they control access. Option D is incorrect because Cloud Run can handle concurrent requests, but a container that doesn't support concurrency will still receive traffic, just one at a time. Therefore, the most likely cause is a port mismatch.
What should I do if I get this ACE question wrong?
Review pORT environment variable, then practise related ACE questions on the same topic to reinforce the concept.
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?
PORT environment variable
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 →
Keep practising
More ACE practice questions
- A team's Cloud Build pipeline must: (1) run unit tests, (2) build a Docker image only if tests pass, (3) push the image…
- A team needs a database backup job to run every day at 2 AM UTC. The job calls an HTTP endpoint to trigger the backup. T…
- A team wants to receive an email alert when the average CPU utilization of VMs in a managed instance group exceeds 80% f…
- A Go service is consuming significantly more CPU than expected. The team suspects an inefficient function but doesn't kn…
- A network team is creating a new VPC and must decide between auto mode and custom mode. Why would they choose custom mod…
- A company organizes its GCP projects by business unit — Finance, Engineering, and Sales. Which resource is best suited t…
Last reviewed: Jul 4, 2026
This ACE 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 ACE 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.