Question 102 of 500
Optimizing service performancemediumMultiple ChoiceObjective-mapped

Quick Answer

The answer is to increase the memory limit and requests for the container. This is correct because frequent GC pauses with high memory usage but low CPU utilization indicate the JVM heap is too small, forcing the garbage collector to run constantly and causing the observed GKE microservice latency. By raising the memory limit, you give the JVM more headroom, reducing GC frequency and directly lowering latency. On the Google Professional Cloud DevOps Engineer exam, this scenario tests your understanding of resource tuning in containerized environments—a common trap is to scale CPU when the bottleneck is memory, not compute. Remember the mnemonic: “Low CPU, high mem, GC screams—raise the heap, not the streams.”

PCDOE Optimizing service performance Practice Question

This PCDOE practice question tests your understanding of optimizing 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 team deploys a microservice on Google Kubernetes Engine (GKE) that processes user uploads. The service latency has increased over time. Monitoring shows that CPU utilization is low, but memory usage is high and garbage collection (GC) pauses are frequent. Which action is most likely to reduce latency?

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.

Question 1mediummultiple choice
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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 memory limit and requests for the container.

Frequent GC pauses and high memory usage with low CPU indicate the JVM heap is too small, causing the garbage collector to run more often. Increasing the memory limit and requests gives the JVM more headroom to reduce GC frequency, directly lowering latency. This is a classic JVM tuning scenario in containerized environments like GKE.

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.

  • Scale out the deployment by increasing the number of replicas.

    Why it's wrong here

    CPU is low, so more replicas won't reduce GC pauses.

  • Reduce the number of replicas to concentrate load.

    Why it's wrong here

    Fewer replicas increase load per pod, worsening GC.

  • Increase the CPU limit to allow faster processing.

    Why it's wrong here

    CPU is not the bottleneck.

  • Increase the memory limit and requests for the container.

    Why this is correct

    More memory reduces GC frequency and pauses.

    Clue confirmation

    The clue word "most likely" in the question point toward this answer.

    Related concept

    Read the scenario before looking for a memorised answer.

Common exam traps

Common exam trap: answer the scenario, not the keyword

Google Cloud often tests the misconception that scaling out or adding CPU fixes all performance issues, but here the symptom of low CPU and high memory with GC pauses specifically points to a memory constraint, not a throughput or compute bottleneck.

Detailed technical explanation

How to think about this question

Under the hood, the JVM's garbage collector (e.g., G1GC) triggers a pause when the heap approaches its maximum size. In Kubernetes, the container's memory limit is the cgroup memory.max, and the JVM uses this to set heap sizes via -XX:MaxRAMPercentage. If the limit is too low, the JVM cannot allocate enough heap, leading to frequent full GCs. A real-world scenario is a Java microservice processing large uploads where object allocation spikes; without enough heap, GC becomes the dominant latency factor.

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

An e-commerce site experiences heavy traffic on Black Friday and near-zero traffic during off-peak weeks. Rather than provisioning permanent large VMs, the team uses auto-scaling groups that add capacity automatically under load and reduce it overnight. Questions like this test whether you understand elasticity, availability zones, and cloud compute scaling patterns.

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 PCDOE question test?

Optimizing service performance — This question tests Optimizing 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 memory limit and requests for the container. — Frequent GC pauses and high memory usage with low CPU indicate the JVM heap is too small, causing the garbage collector to run more often. Increasing the memory limit and requests gives the JVM more headroom to reduce GC frequency, directly lowering latency. This is a classic JVM tuning scenario in containerized environments like GKE.

What should I do if I get this PCDOE 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: "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.

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Last reviewed: Jun 30, 2026

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This PCDOE 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 PCDOE exam.