Question 836 of 1,000
Google Cloud products, services, and solutionseasyMultiple ChoiceObjective-mapped

Autoscaling with MIGs and Cloud Run

This GCDL practice question tests your understanding of google cloud products, services, and solutions. 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 startup's website becomes unexpectedly popular and traffic spikes 50x within minutes. The application is hosted on Google Cloud. Which Google Cloud product automatically increases the number of application instances in response to this traffic spike without manual intervention?

Quick Answer

The answer is Managed Instance Groups with autoscaling or Cloud Run, as both automatically increase application instances in response to a sudden 50x traffic spike without manual intervention. This works because autoscaling monitors real-time metrics like CPU utilization or request rate; when load surges, the autoscaler provisions new VMs in a MIG or additional container replicas in Cloud Run to handle the demand. On the Google Cloud Digital Leader exam, this tests your understanding of infrastructure-level scaling versus manual or scheduled scaling—a common trap is choosing a load balancer alone, which distributes traffic but does not create instances. Remember, autoscaling is reactive to load, not proactive. A simple memory tip: “MIGs and Cloud Run both auto-scale; a load balancer just mails the mail.”

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

Managed Instance Groups with autoscaling (for VMs) or Cloud Run (for containers), which automatically provision additional instances based on traffic load without manual intervention

Managed Instance Groups (MIGs) with autoscaling and Cloud Run both automatically adjust the number of running instances or container replicas based on real-time metrics like CPU utilization, request rate, or latency. When traffic spikes 50x, the autoscaler detects the increased load and provisions new VMs or container instances without any manual intervention, ensuring the application remains responsive. This is the only option that provides automatic, infrastructure-level scaling in response to load.

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.

  • Cloud Monitoring, which detects the traffic spike and sends an alert to the operations team to manually scale up

    Why it's wrong here

    Cloud Monitoring provides detection and alerting but not automatic scaling. Manual intervention is too slow for a 50x traffic spike that happens within minutes. Automatic scaling is needed.

  • Managed Instance Groups with autoscaling (for VMs) or Cloud Run (for containers), which automatically provision additional instances based on traffic load without manual intervention

    Why this is correct

    This is correct. MIG autoscaling monitors CPU/request metrics and automatically adds instances when load increases, then removes them when load drops. Cloud Run scales automatically to any number of container instances in seconds. Both handle the 50x spike scenario automatically.

    Related concept

    Read the scenario before looking for a memorised answer.

  • Cloud Load Balancing, which distributes traffic evenly across existing instances to handle the spike

    Why it's wrong here

    Load balancing distributes traffic across existing instances but doesn't add new instances. If the existing instances are overwhelmed by a 50x spike, load balancing alone can't help — more capacity must be added automatically.

  • Cloud Billing, which automatically increases the spending limit when traffic spikes occur

    Why it's wrong here

    Cloud Billing manages costs and budgets. It has no role in provisioning capacity or scaling infrastructure.

Common exam traps

Common exam trap: answer the scenario, not the keyword

The GCDL exam often tests the misconception that load balancing alone handles spikes, but candidates must remember that load balancers distribute traffic only to existing instances — autoscaling is required to add capacity.

Detailed technical explanation

How to think about this question

Under the hood, MIG autoscaling uses a target metric (e.g., CPU utilization at 60%) and a cool-down period to avoid thrashing; it can scale based on Stackdriver metrics or HTTP load balancing utilization. Cloud Run uses Knative-based autoscaling with a concurrency target (e.g., 80 concurrent requests per container) and can scale to zero when idle, making it ideal for unpredictable spikes. A real-world scenario: a startup's blog post goes viral — Cloud Run can scale from 0 to thousands of containers in seconds, while MIGs might take minutes to provision new VMs.

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 startup's cloud architect reviews their monthly bill and notices costs are higher than expected for a long-running batch job. Switching from on-demand instances to Reserved Instances — or using Spot/Preemptible VMs — can reduce compute costs by up to 72 %. Questions like this test whether you understand the tradeoffs between commitment, flexibility, and cost across cloud pricing models.

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 GCDL question test?

Google Cloud products, services, and solutions — This question tests Google Cloud products, services, and solutions — Read the scenario before looking for a memorised answer..

What is the correct answer to this question?

The correct answer is: Managed Instance Groups with autoscaling (for VMs) or Cloud Run (for containers), which automatically provision additional instances based on traffic load without manual intervention — Managed Instance Groups (MIGs) with autoscaling and Cloud Run both automatically adjust the number of running instances or container replicas based on real-time metrics like CPU utilization, request rate, or latency. When traffic spikes 50x, the autoscaler detects the increased load and provisions new VMs or container instances without any manual intervention, ensuring the application remains responsive. This is the only option that provides automatic, infrastructure-level scaling in response to load.

What should I do if I get this GCDL question wrong?

Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.

What is the key concept behind this question?

Read the scenario before looking for a memorised answer.

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Last reviewed: Jun 11, 2026

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This GCDL 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 GCDL exam.