- A
Deploy v2 to a new endpoint and update your clients to use the new endpoint.
Why wrong: This does not allow gradual shifting; it's a cut-over.
- B
Use Vertex AI Experiments to compare v1 and v2, then redeploy v2 with 100% traffic.
Why wrong: Experiments are for training, not serving traffic management.
- C
Update the traffic split configuration on the endpoint multiple times over the 3 days to gradually increase v2's percentage.
This is the correct method for gradual traffic shifting.
- D
Delete v1 from the endpoint so that all traffic automatically goes to v2.
Why wrong: This is abrupt and risky.
Question 122 of 1,000
PMLE Serving and Scaling Models Practice Question
This PMLE practice question tests your understanding of serving and scaling models. 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.
You have a Vertex AI endpoint with two deployed models: a champion (v1) and a challenger (v2). You set the traffic split to 90% v1 and 10% v2. After a week, you observe that v2 has better business metrics. You want to shift all traffic to v2 gradually over 3 days to avoid any risk. What should you do?
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
✓
Update the traffic split configuration on the endpoint multiple times over the 3 days to gradually increase v2's percentage.
Option C is correct because Vertex AI endpoints support live traffic splitting between deployed models, allowing you to gradually shift traffic from v1 to v2 by updating the traffic split configuration multiple times over the 3-day period. This approach minimizes risk by enabling incremental rollouts and immediate rollback if issues arise, without requiring client-side changes or downtime.
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.
- ✗
Deploy v2 to a new endpoint and update your clients to use the new endpoint.
Why it's wrong here
This does not allow gradual shifting; it's a cut-over.
- ✗
Use Vertex AI Experiments to compare v1 and v2, then redeploy v2 with 100% traffic.
Why it's wrong here
Experiments are for training, not serving traffic management.
- ✓
Update the traffic split configuration on the endpoint multiple times over the 3 days to gradually increase v2's percentage.
Why this is correct
This is the correct method for gradual traffic shifting.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Delete v1 from the endpoint so that all traffic automatically goes to v2.
Why it's wrong here
This is abrupt and risky.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates may assume deleting the old model or redeploying with 100% traffic is acceptable, but the question explicitly requires a gradual shift over 3 days to avoid risk, which only incremental traffic split updates can achieve.
Detailed technical explanation
How to think about this question
Under the hood, Vertex AI endpoints use a traffic split mechanism based on a weighted random selection at the load balancer level, where each request is routed to a model according to the configured percentages. This allows for canary deployments and A/B testing in production without redeploying or modifying client code. In a real-world scenario, you might start with 90/10, then move to 70/30, 50/50, 30/70, and finally 0/100 over the 3 days, monitoring error rates and latency at each step to ensure stability.
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.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
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FAQ
Questions learners often ask
What does this PMLE question test?
Serving and Scaling Models — This question tests Serving and Scaling Models — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Update the traffic split configuration on the endpoint multiple times over the 3 days to gradually increase v2's percentage. — Option C is correct because Vertex AI endpoints support live traffic splitting between deployed models, allowing you to gradually shift traffic from v1 to v2 by updating the traffic split configuration multiple times over the 3-day period. This approach minimizes risk by enabling incremental rollouts and immediate rollback if issues arise, without requiring client-side changes or downtime.
What should I do if I get this PMLE question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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Last reviewed: Jul 4, 2026
This PMLE 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 PMLE exam.
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