Question 1,392 of 1,616
Troubleshooting and OptimizationmediumMultiple ChoiceObjective-mapped

DVA-C02 Eviction Policy Practice Question

This DVA-C02 practice question tests your understanding of troubleshooting and optimization. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. A key principle to apply: eviction Policy. 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 developer is troubleshooting an application that uses Amazon ElastiCache for Redis to cache database query results. The application experiences high latency during cache misses. The developer notices that frequently accessed keys (hot keys) are often missing from the cache, suggesting they are being evicted. Which action should the developer take to reduce cache misses for hot keys?

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

Switch to the 'allkeys-lru' eviction policy.

Option B is correct because the 'allkeys-lru' eviction policy allows Redis to evict any key (including those with TTL) based on least-recently-used access, which helps retain frequently accessed hot keys. By default, ElastiCache for Redis uses the 'volatile-lru' policy, which only evicts keys with an expiration set, leaving hot keys without TTL vulnerable to eviction when memory pressure occurs. Switching to 'allkeys-lru' ensures that even keys without TTL can be considered for eviction, reducing the likelihood of hot keys being removed.

Key principle: Eviction Policy

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 number of cache nodes.

    Why it's wrong here

    Adding nodes increases total memory but does not change how eviction selects keys; hot keys may still be evicted if not properly prioritized.

  • Switch to the 'allkeys-lru' eviction policy.

    Why this is correct

    allkeys-lru evicts the least recently used keys from all keys, which tends to retain frequently used hot keys.

    Related concept

    Eviction Policy

  • Disable the TTL on all cached keys.

    Why it's wrong here

    Disabling TTL can cause the cache to fill with stale data and increase memory pressure, potentially worsening eviction of hot keys.

  • Increase the size of the cache cluster.

    Why it's wrong here

    More memory can reduce eviction frequency, but if the eviction policy is not LRU-based, hot keys may still be evicted in favor of other keys.

Common exam traps

Common exam trap: answer the scenario, not the keyword

The trap here is that candidates assume scaling up or out is the only solution for cache misses, overlooking that the eviction policy directly controls which keys are removed under memory pressure, and 'volatile-lru' by default excludes keys without TTL from eviction consideration.

Detailed technical explanation

How to think about this question

Under the hood, Redis uses an approximation of LRU (not exact LRU) to minimize overhead, sampling a small pool of keys (default 5) to evict. The 'allkeys-lru' policy treats all keys equally, while 'volatile-lru' only considers keys with an explicit TTL set. In real-world scenarios, hot keys often have no TTL because they are expected to stay cached indefinitely, making them prime candidates for eviction under 'volatile-lru' when memory fills up with other keys that do have TTL.

KKey Concepts to Remember

  • Eviction Policy
  • allkeys-lru
  • Hot Key
  • volatile-lru

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

Eviction Policy

Real-world example

How this comes up in practice

A company's IT admin needs to give a contractor read-only access to production logs without sharing account credentials. Using role-based access control (RBAC) and temporary scoped permissions — not a permanent shared password — is the correct pattern. Questions like this test whether you can apply least-privilege access across cloud identity services.

What to study next

Got this wrong? Here's your next step.

Review eviction Policy, then practise related DVA-C02 questions on the same topic to reinforce the concept.

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FAQ

Questions learners often ask

What does this DVA-C02 question test?

Troubleshooting and Optimization — This question tests Troubleshooting and Optimization — Eviction Policy.

What is the correct answer to this question?

The correct answer is: Switch to the 'allkeys-lru' eviction policy. — Option B is correct because the 'allkeys-lru' eviction policy allows Redis to evict any key (including those with TTL) based on least-recently-used access, which helps retain frequently accessed hot keys. By default, ElastiCache for Redis uses the 'volatile-lru' policy, which only evicts keys with an expiration set, leaving hot keys without TTL vulnerable to eviction when memory pressure occurs. Switching to 'allkeys-lru' ensures that even keys without TTL can be considered for eviction, reducing the likelihood of hot keys being removed.

What should I do if I get this DVA-C02 question wrong?

Review eviction Policy, then practise related DVA-C02 questions on the same topic to reinforce the concept.

What is the key concept behind this question?

Eviction Policy

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Last reviewed: Jun 11, 2026

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This DVA-C02 practice question is part of Courseiva's free Amazon Web Services 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 DVA-C02 exam.