The answer is `gcloud app services set-traffic default --splits v1=0.9,v2=0.1` because it directly assigns traffic percentages to specific App Engine versions without requiring a new deployment or promoting a version to receive all traffic. This command works by targeting the "default" service and using the `--splits` flag to define a weighted distribution, where the sum of the fractions must equal 1.0, making it the precise tool for gradual traffic migration between versions in the App Engine standard environment. On the Google Associate Cloud Engineer exam, this tests your understanding of traffic management versus version promotion—a common trap is confusing `set-traffic` with `deploy` or `promote`, which would shift 100% of traffic. Remember that `set-traffic` is for splitting, not deploying. A helpful memory tip: think of the `--splits` flag as a pie chart where each version gets a slice, and the total must always add up to a whole pie.
Google ACE Deploying and implementing a cloud solution Practice Question
This ACE practice question tests your understanding of deploying and implementing a cloud solution. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. 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.
You need to deploy a new version of an App Engine standard environment application. The new version should receive 10% of traffic while the current version continues to receive 90%. Which command achieves this?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "which command"
Why it matters: Tests specific CLI syntax. Recall the exact command and its required context — near-synonyms and partial matches are common distractors.
Why wrong: `--no-promote` deploys the new version without routing any traffic to it (0%). Additional traffic-split configuration is needed to send 10%.
Option B is correct because the `gcloud app services set-traffic` command explicitly splits traffic between versions of an App Engine service. By specifying `--splits v1=0.9,v2=0.1`, you direct 90% of requests to version v1 and 10% to version v2, without deploying a new version or promoting it. This is the standard method for gradual traffic migration in App Engine standard environment.
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.
✗
`gcloud app deploy --version=v2 --no-promote`
Why it's wrong here
`--no-promote` deploys the new version without routing any traffic to it (0%). Additional traffic-split configuration is needed to send 10%.
This promotes v2 to receive 100% of traffic and stops v1 — the opposite of the required 10/90 split.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Google Cloud often tests the distinction between deploying a version (`deploy`), migrating all traffic (`migrate`), and splitting traffic (`set-traffic`), so the trap here is that candidates confuse `--no-promote` with traffic splitting, thinking it allocates a percentage of traffic when it actually just deploys without routing any traffic to the new version.
Detailed technical explanation
How to think about this question
App Engine traffic splitting uses a configurable router that distributes incoming HTTP requests based on a weighted random selection, with the split defined as a map of version IDs to integer percentages (e.g., 0.9 and 0.1). The `set-traffic` command updates the service's traffic configuration in the `app.yaml` or via the Admin API, and the router applies the split at the edge, ensuring session affinity (cookie-based) if needed. This is commonly used for canary deployments or A/B testing, where gradual rollout reduces risk.
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.
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
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.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this ACE question in full detail.
Deploying and implementing a cloud solution — This question tests Deploying and implementing a cloud solution — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: `gcloud app services set-traffic default --splits v1=0.9,v2=0.1` — Option B is correct because the `gcloud app services set-traffic` command explicitly splits traffic between versions of an App Engine service. By specifying `--splits v1=0.9,v2=0.1`, you direct 90% of requests to version v1 and 10% to version v2, without deploying a new version or promoting it. This is the standard method for gradual traffic migration in App Engine standard environment.
What should I do if I get this ACE question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "which command". Tests specific CLI syntax. Recall the exact command and its required context — near-synonyms and partial matches are common distractors.
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 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.