Google PCA Ensure solution and operations reliability Practice Question
Exhibit
Refer to the exhibit.
# Sample managed instance group configuration (YAML)
resource:
type: compute.beta.instanceGroupManager
properties:
zone: us-central1-a
targetSize: 3
baseInstanceName: my-app
instanceTemplate: global/instanceTemplates/my-template
autoHealingPolicies:
- healthCheck: global/healthChecks/http-health-check
initialDelaySec: 300
autoScaler:
minNumReplicas: 3
maxNumReplicas: 10
coolDownPeriodSec: 60
cpuUtilization:
utilizationTarget: 0.6The exhibit shows a managed instance group configuration. What is the primary purpose of the 'autoHealingPolicies' section?
⚠ Common exam trap
Google Cloud often tests the distinction between 'autohealing' (health-based instance replacement) and 'autoscaling' (metric-based instance count adjustment), causing candidates to confuse the purpose of the 'autoHealingPolicies' section with scaling policies.
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
✓
Automatically replace instances that are deemed unhealthy based on the health check.
The 'autoHealingPolicies' section in a managed instance group configuration is specifically designed to automatically replace instances that are deemed unhealthy based on a configured health check. When a health check probe (e.g., HTTP, TCP, or SSL) fails for a sustained period, the managed instance group terminates the unhealthy instance and creates a new one from the instance template, ensuring the desired number of healthy instances is maintained. This is distinct from autoscaling, which adjusts instance count based on load metrics.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Distribute incoming traffic evenly across the instances.
Why it's wrong here
Traffic distribution is handled by load balancing, such as a backend service or HTTP(S) load balancer, not autoHealingPolicies. Autohealing instead monitors instance health and recreates failed instances; even distribution across instances is the load balancer's function.
- ✗
Automatically add more instances when CPU utilization exceeds 60%.
Why it's wrong here
Adding instances on CPU load is autoscaling, configured via autoscaling policies, not autoHealingPolicies. Autohealing responds to failed health checks by recreating instances; scaling out on utilisation thresholds is what you would set when demand varies and capacity must grow automatically.
- ✓
Automatically replace instances that are deemed unhealthy based on the health check.
Why this is correct
Autohealing policies continuously run the specified health check against each instance; any instance failing it is deleted and recreated by the managed instance group, restoring the desired capacity. This directly satisfies the stem's requirement to remediate unhealthy instances automatically, rather than merely scaling or distributing traffic.
- ✗
Automatically update instances to a new instance template.
Why it's wrong here
autoHealingPolicies recreates unhealthy instances based on health checks, not rolling out new templates. Updating instances to a new template is the role of an update policy or rolling update, which is what you would configure when deploying a revised image across the group.
Go deeper
Related to this question
Learn chapter
Virtual Machine Instances in Compute Engine
Key term
Instance template
An instance template is a reusable configuration blueprint that defines the virtual machine settings, such as machine type, boot disk image, and network, for creating identical VM instances in Google Cloud Platform.
Key term
Health check
A health check is an automated test that monitors whether a system, application, container, or network service is running correctly and can respond to requests.
About these practice questions
One of 807 original PCA practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This PCA 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 PCA exam.