Compute Engine Sustained-Use Discount Application

CDL By islever Editorial Last updated Sep 12, 2026

Short answer

C Nothing. Sustained use discounts are automatically applied to Compute Engine VMs running for a significant portion of the billing cycle.

Question

An organization is using Compute Engine and wants to receive sustained-use discounts. What should the organization do?

Choose preemptible or spot instances when creating virtual machines.
Choose low-powered virtual machines.
Nothing. Sustained use discounts are automatically applied. Correct Answer
Commit to virtual machine usage for a one or three-year period.

Key Takeaways

The exam tests the distinction between automatic sustained-use discounts and manual committed-use discounts; the trap is confusing 'sustained' with 'committed'.

Sustained-use discounts in Google Cloud Compute Engine are automatically applied when VMs run for a significant portion of the billing cycle. This page clarifies that no manual commitment is required, distinguishing them from Committed Use Discounts.

Common mistake: Many learners choose D because they confuse 'sustained use' (automatic) with 'committed use' (requires 1-3 year contract). The term 'sustained' implies continuous running, not a financial commitment.

Expert Analysis

Why the Answer Is Correct

The correct answer is C. Google Cloud Platform applies sustained-use discounts automatically to Compute Engine instances that run continuously for a significant part of the month. According to official documentation, these discounts are calculated based on usage hours and appear on the bill without any user action or pre-commitment.

Why the Other Options Are Wrong

Option A refers to preemptible/spot instances, which offer lower prices but have different interruption policies and do not qualify for sustained-use discounts in the same way. Option B is incorrect as instance power level does not determine discount eligibility. Option D describes Committed Use Discounts (CUDs), which require a 1-year or 3-year financial commitment, whereas sustained-use discounts are purely usage-based and automatic.

Community Comment Notes

The community majority correctly identified C. User xdkonorek2 noted that sustained-use discounts are automatic based on usage percentage, contrasting them with committed usage discounts. User SpenceC provided an official link confirming that these discounts appear automatically on the bill. User sallymaher incorrectly argued for D, confusing the two distinct discount types, which highlights the common trap this question presents.

Official Reference

https://cloud.google.com/compute/docs/sustained-use-discounts

This link opens the official vendor documentation in a new tab.

Exam Strategy

Always distinguish between 'Sustained Use' (automatic, usage-based) and 'Committed Use' (manual, contract-based). If the question asks about 'sustained', look for 'automatic' or 'no action required'. If it asks about 'commitment', look for contracts.

Frequently Asked Questions

Why is option D wrong for sustained-use discounts?

Option D describes Committed Use Discounts, which require a 1-3 year contract. Sustained-use discounts are automatic and based on monthly runtime, not a financial commitment.

Do I need to enable sustained-use discounts manually?

No. As stated in the correct answer, these discounts are automatically applied by Google Cloud when your VMs run for more than 25% of the month.

More CDL FAQ →

Community Votes

80%

20%

80% of anonymous learners picked answer C. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 5 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 5

sallymaher 👍 2

The correct answer is D. Commit to virtual machine usage for a one or three-year period. Here's a breakdown of why: Sustained-use discounts: These discounts are offered by Google Cloud Platform (GCP) for consistent usage of virtual machines over a specified period. Commitment options: To qualify for sustained-use discounts, organizations can commit to using virtual machines for either one or three years. This commitment provides GCP with a predictable workload, allowing them to optimize resource allocation and offer discounted rates.
xdkonorek2 👍 2 Answered C

question asks specifically for sustained use discounts which are applied automatically based on % of VM usage over month in contrast of committed usage discounts which would require 1 or 3 commitment
joshnort 👍 1 Answered C

C. Nothing. Sustained use discounts are automatically applied. Sustained use discounts are automatically applied to Google Cloud Compute Engine virtual machines (VMs) when they are used for a significant portion of the month (e.g., more than 25% of the month). These discounts are automatic and do not require any action from the user, as long as the VMs are running for extended periods.
SpenceC 👍 1 Answered C

Sustained use discounts automatically appear on your bill at the end of the billing cycle. https://cloud.google.com/compute/docs/sustained-use-discounts#:~:text=Sustained%20use%20discounts%20are%20a,Google%20Cloud%20console%20billing%20history.
fca3eaa 👍 1 Answered D

The correct answer is D

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