Cloud Digital Leader Google Cloud Products and Services Practice Question
A company runs a stateful web application on Compute Engine. They need to ensure that persistent data is retained if an instance fails, and that traffic is automatically distributed across healthy instances. Which TWO Google Cloud services should they use? (Choose 2)
⚠ Common exam trap
GCDL often tests the misconception that any GCP networking service (Cloud DNS, Cloud CDN, Cloud NAT) provides storage or load balancing — candidates must map each service to its actual function.
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
✓
Persistent Disk
Persistent Disk (B) is correct because it provides durable, network-attached block storage that persists independently of the Compute Engine instance lifecycle, so data survives an instance failure and can be reattached to a replacement VM. Cloud Load Balancing (C) is correct because it automatically distributes incoming traffic across healthy backend instances using health checks, removing unhealthy instances from rotation. Cloud DNS (A) only resolves domain names to IP addresses and does not provide persistence or health-based traffic distribution. Cloud CDN (D) caches HTTP(S) content at edge locations to reduce latency, not to persist application data or balance traffic. Cloud NAT (E) provides outbound internet access for private instances and does not address storage durability or load distribution.
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 DNS
Why it's wrong here
Cloud DNS provides domain name resolution, translating domain names to IP addresses, but its responsibility stops after returning DNS records. It does not distribute incoming traffic based on backend health, nor does it persist any application state. For a stateful web application, Cloud DNS cannot store session data or contribute to high availability beyond enabling clients to locate the service.
- ✓
Persistent Disk
Why this is correct
Persistent Disk stores durable block-level data that exists independently of the virtual machine instance. When an instance is terminated or fails, the disk can be attached to a new instance in the same zone (or across zones with regional persistent disks), allowing the application to recover all state such as user sessions and database files. This independence is exactly what makes a stateful application resilient to instance-level failures.
- ✓
Cloud Load Balancing
Why this is correct
Cloud Load Balancing distributes incoming traffic across healthy instances in a managed instance group, providing horizontal scaling and fault tolerance. It performs health checks and routes requests to available backends, but it does not store session data or any application state. It complements Persistent Disk by ensuring users can reach surviving instances that share the same underlying durable storage, without itself handling persistence.
- ✗
Cloud CDN
Why it's wrong here
Cloud CDN caches static and dynamic content at global edge locations to reduce latency and lower load on origin servers. It does not provide persistent storage for application state, nor does it balance traffic for reliability; in fact, it may serve stale cached responses if the origin is down. Cached objects are ephemeral and not tied to the application's durable state, so Cloud CDN cannot help maintain state across instance failures.
- ✗
Cloud NAT
Why it's wrong here
Cloud NAT enables private instances without external IP addresses to make outbound connections to the internet via Source Network Address Translation. It applies only to egress traffic, so it does not handle inbound user requests, distribute load, or persist data. For a stateful web application, Cloud NAT is irrelevant to the core requirements of data persistence and traffic distribution.
Visual reference
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Key term
Cloud CDN
A Cloud CDN is a network of servers spread around the world that stores copies of your website or app content so it loads faster for users no matter where they are.
Key term
Cloud Load Balancing
Cloud Load Balancing is the process of distributing incoming network traffic across multiple servers or resources in the cloud to ensure no single resource is overwhelmed, improving availability and reliability.
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Google Cloud exam blueprint
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.