Question 399 of 997
Cloud Native ArchitecturehardMultiple ChoiceObjective-mapped

Istio Service Mesh Latency — Sidecar Proxy Misconfiguration | Kubernetes and Cloud Native Associate Explained

This KCNA practice question tests your understanding of cloud native architecture. 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.

A cloud-native application uses a service mesh (Istio) for traffic management. The team notices increased latency in inter-service communication. Which likely cause should be investigated first?

Clue words in this question

Noticing these words before you look at the options changes how you read each choice.

  • Clue: "first"

    Why it matters: Order matters here. You are being tested on which action comes before the others — not which action is generally useful.

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

Misconfigured sidecar proxy settings

In Istio, the sidecar proxy (Envoy) intercepts all inbound and outbound traffic for the application container. Misconfigured proxy settings—such as incorrect timeouts, retry policies, or circuit breaker thresholds—can introduce significant latency by causing unnecessary retries, connection delays, or queueing. This is the most common and immediate cause of increased latency in a service mesh, as the data plane is directly in the request path.

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.

  • Kubernetes Network Policies blocking traffic

    Why it's wrong here

    Would cause errors, not just latency.

  • Misconfigured sidecar proxy settings

    Why this is correct

    Can cause significant latency.

    Clue confirmation

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

    Related concept

    Read the scenario before looking for a memorised answer.

  • Application code is not optimized for the mesh

    Why it's wrong here

    Code doesn't change.

  • mTLS encryption overhead

    Why it's wrong here

    Overhead is minimal.

Common exam traps

Common exam trap: answer the scenario, not the keyword

CNCF often tests the misconception that mTLS encryption is a major source of latency, but in practice its overhead is negligible compared to misconfigured proxy settings that directly impact request handling.

Detailed technical explanation

How to think about this question

Envoy sidecar proxies use a configuration model based on xDS APIs (LDS, RDS, CDS, etc.) to dynamically update routing rules. A misconfiguration like an overly aggressive retry budget (e.g., retry_on with a high number of attempts) can cause cascading failures and exponential backoff delays. In real-world scenarios, teams often overlook the default Envoy connection pool settings, which can lead to head-of-line blocking if the pool is too small for the traffic burst.

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 practitioner preparing for the KCNA exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.

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.

Related practice questions

Related KCNA practice-question pages

Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.

Practice this exam

Start a free KCNA 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 KCNA question test?

Cloud Native Architecture — This question tests Cloud Native Architecture — Read the scenario before looking for a memorised answer..

What is the correct answer to this question?

The correct answer is: Misconfigured sidecar proxy settings — In Istio, the sidecar proxy (Envoy) intercepts all inbound and outbound traffic for the application container. Misconfigured proxy settings—such as incorrect timeouts, retry policies, or circuit breaker thresholds—can introduce significant latency by causing unnecessary retries, connection delays, or queueing. This is the most common and immediate cause of increased latency in a service mesh, as the data plane is directly in the request path.

What should I do if I get this KCNA 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: "first". Order matters here. You are being tested on which action comes before the others — not which action is generally useful.

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 →

How Courseiva writes practice questions · Editorial policy

Keep practising

More KCNA practice questions

Last reviewed: Jun 30, 2026

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.

Loading comments…

Sign in to join the discussion.

This KCNA practice question is part of Courseiva's free CNCF 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 KCNA exam.