- A
Increase the acknowledgement deadline to give subscribers more time to process messages
A longer acknowledgement deadline reduces the chance of redelivery due to timeout, allowing more time for processing.
- B
Enable message ordering keys to ensure orderly processing
Why wrong: Ordering keys reduce parallelism because messages with the same key must be processed sequentially, lowering throughput.
- C
Change the subscription type from pull to push for faster delivery
Why wrong: Subscription type cannot be changed after creation; also, push may have different limitations.
- D
Increase the number of parallel pull consumers in the subscriber
More parallel pull consumers increase the rate of message delivery, improving throughput.
- E
Decrease the flow control max outstanding messages to reduce load on subscribers
Why wrong: Decreasing flow control would limit the number of messages pulled, reducing throughput.
PCDE Optimising Service Performance Practice Question
This PCDE practice question tests your understanding of optimising service performance. 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.
A DevOps team is using Pub/Sub to process high-volume event streams. They notice that the subscriber is falling behind and messages are being redelivered frequently. They need to increase throughput. Which TWO actions should they take? (Choose TWO)
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
Increase the acknowledgement deadline to give subscribers more time to process messages
Increasing the acknowledgement deadline gives subscribers more time to process messages, reducing redeliveries. Using multiple parallel pull consumers increases the rate at which messages are pulled. Flow control should be increased, not decreased, to allow more outstanding messages. Ordering keys reduce throughput because they limit parallelism. Subscription type is fixed at creation time.
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.
- ✓
Increase the acknowledgement deadline to give subscribers more time to process messages
Why this is correct
A longer acknowledgement deadline reduces the chance of redelivery due to timeout, allowing more time for processing.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Enable message ordering keys to ensure orderly processing
Why it's wrong here
Ordering keys reduce parallelism because messages with the same key must be processed sequentially, lowering throughput.
- ✗
Change the subscription type from pull to push for faster delivery
Why it's wrong here
Subscription type cannot be changed after creation; also, push may have different limitations.
- ✓
Increase the number of parallel pull consumers in the subscriber
Why this is correct
More parallel pull consumers increase the rate of message delivery, improving throughput.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Decrease the flow control max outstanding messages to reduce load on subscribers
Why it's wrong here
Decreasing flow control would limit the number of messages pulled, reducing throughput.
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 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 PCDE 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.
- →
Optimising Service Performance — study guide chapter
Learn the concepts, then practise the questions
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Optimising Service Performance practice questions
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FAQ
Questions learners often ask
What does this PCDE question test?
Optimising Service Performance — This question tests Optimising Service Performance — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Increase the acknowledgement deadline to give subscribers more time to process messages — Increasing the acknowledgement deadline gives subscribers more time to process messages, reducing redeliveries. Using multiple parallel pull consumers increases the rate at which messages are pulled. Flow control should be increased, not decreased, to allow more outstanding messages. Ordering keys reduce throughput because they limit parallelism. Subscription type is fixed at creation time.
What should I do if I get this PCDE question wrong?
Identify which PCDE 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.
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 →
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Last reviewed: Jul 4, 2026
This PCDE 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 PCDE exam.
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