Cloud Digital Leader Fundamental Cloud Concepts Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  Regional load balancer

  Why it's wrong here

  A regional load balancer is a Layer 4/7 traffic distribution service that sits in front of your VM instances and forwards requests based on routing rules, backend services, and load-balancing schemes. While it does use health checks to determine which backends are healthy and stops sending traffic to unhealthy instances, it never takes lifecycle actions — it cannot terminate, recreate, or restart a VM. Unhealthy instances simply remain stopped or degraded until an external mechanism, such as a managed instance group, replaces them, so a load balancer alone does not satisfy the requirement to auto-recover web servers.

• ✓

  Managed instance group (MIG)

  Why this is correct

  A managed instance group (MIG) is a Google Compute Engine resource that manages a collection of VM instances created from an instance template. It supports autoscaling to add or remove instances based on load, but more importantly it supports autohealing: when you configure a health check, the MIG continuously monitors each instance and automatically deletes and recreates any instance that fails that health check. This makes the MIG the correct enabling service because it provides the instance-management layer that can actually replace unhealthy VMs, keeping the e-commerce site resilient without manual intervention.

• ✓

  Autohealing (health checks)

  Why this is correct

  Autohealing in Compute Engine is the health-check-driven process that detects instances that have become unresponsive or failed their application-level health check and then recycles them. Health checks probe the instance's IP on a specified port and path (e.g., HTTP 200 on /healthz); when a configurable number of consecutive failures occurs, the instance is marked unhealthy and the managed instance group automatically terminates and recreates it. Autohealing is not a standalone Google Cloud product but a built-in feature of MIGs, and it is the exact mechanism that performs the replacement, making it a correct answer along with MIG itself.

• ✗

  Cloud CDN

  Why it's wrong here

  Cloud CDN is a caching service that stores static content at Google's global edge locations to improve latency and reduce the load on your origins. It does not probe instance liveness, perform health checks, or take any recovery actions; when a backend instance fails, Cloud CDN may simply continue serving cached responses, which can even hide the failure from users. It has no capability to manage the instance group, restart VMs, or trigger a replacement, so it is purely a performance optimization layer, not a health management or autohealing service.

• ✗

  Cloud NAT

  Why it's wrong here

  Cloud NAT is a managed network address translation service that allows private VM instances without external IP addresses to initiate outbound connections to the internet while preventing inbound connections from reaching them. It works at the network layer and has no awareness of application instance health, no health check probes, and no ability to modify VM lifecycle. Cloud NAT's sole purpose is to provide secure outbound connectivity for private networks, so it is irrelevant to detecting or replacing unhealthy web servers in a managed instance group.

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