hardMultiple ChoiceObjective-mapped
CV0-004 Practice Question: Migrating its on-premises e-commerce application…
A company is migrating its on-premises e-commerce application to a public cloud. The application consists of a stateless web tier, a stateful application tier that stores session data in memory, and a relational database. The migration must ensure high availability, scalability, and minimal downtime during cutover. The cloud provider offers load balancers, auto-scaling groups, managed database services, and caching services. The current on-premises architecture uses a single web server, a single application server, and a single database server. The application tier stores session data in local memory, which is lost if the server fails. The team needs to redesign the architecture to be cloud-native. Which of the following is the BEST course of action?
⚠ Common exam trap
CompTIA often tests the misconception that sticky sessions or session replication are sufficient for high availability in a cloud environment, but the correct approach is to externalize session state to a distributed cache to achieve true statelessness and scalability.
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
✓
Deploy the web tier behind a load balancer with auto-scaling. Move session state from the application tier to a distributed caching service. Deploy the application tier behind a separate load balancer with auto-scaling. Migrate the database to a managed Multi-AZ deployment.
It addresses the key requirements: high availability, scalability, and minimal downtime. By moving session state from local memory to a distributed caching service (e.g., Amazon ElastiCache or Azure Cache for Redis), the application tier becomes stateless and can be auto-scaled behind its own load balancer. The managed Multi-AZ database provides automatic failover and high availability, while the web tier behind a load balancer with auto-scaling ensures scalability and fault tolerance. This design eliminates single points of failure and allows zero-downtime cutover by scaling out before decommissioning on-premises resources.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Deploy the web tier behind a load balancer with auto-scaling. Keep the application tier as a single instance with session replication to a secondary instance. Use a managed database with a read replica.
Why it's wrong here
While this improves scalability for the web tier, the application tier remains stateful and session replication to a single secondary does not provide full high availability; a distributed cache would be better.
- ✓
Deploy the web tier behind a load balancer with auto-scaling. Move session state from the application tier to a distributed caching service. Deploy the application tier behind a separate load balancer with auto-scaling. Migrate the database to a managed Multi-AZ deployment.
Why this is correct
This design is fully cloud-native: the web and application tiers are stateless and auto-scaled, session state is stored externally in a highly available cache, and the database is managed with Multi-AZ for high availability.
- ✗
Use a load balancer for the web tier with auto-scaling. Deploy the application tier as a single large instance with sticky sessions. Migrate the database to a larger single-instance managed database.
Why it's wrong here
Sticky sessions tie a user to a specific instance, reducing scalability and availability. The database is still a single point of failure.
- ✗
Deploy both web and application tiers behind a load balancer with auto-scaling. Use sticky sessions to maintain session state. Migrate the database to a managed Multi-AZ deployment.
Why it's wrong here
Sticky sessions limit scalability because sessions are tied to specific instances. The application tier still stores session data in memory, which is lost if the instance fails.
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Same concept, more angles
2 more ways this is tested on CV0-004
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A company runs a critical application on a cloud VM that must achieve a 99.99% monthly uptime SLA. The VM is deployed in a single availability zone. The current architecture has no redundancy. What is the most effective design change to meet the SLA requirement?
hard- A.Schedule daily backups to a different region
- ✓ B.Deploy the application across two availability zones with a load balancer
- C.Upgrade the VM to a larger instance type for better reliability
- D.Add a second VM in the same availability zone with a load balancer
Why B: Deploying the application across two availability zones with a load balancer provides high availability by eliminating a single point of failure. A 99.99% monthly uptime SLA requires a design that can withstand an entire availability zone failure, which a single-zone deployment cannot achieve. The load balancer distributes traffic to healthy VMs, automatically failing over if one zone becomes unavailable, thus meeting the SLA target.
Variation 2. A cloud architect is designing a multi-tier web application in a cloud environment. The application must handle unpredictable traffic spikes while minimizing costs. The architect decides to use auto-scaling groups for the web tier and a managed database service for the data tier. Which additional design consideration is MOST important to ensure the application remains available during a regional outage?
medium- ✓ A.Distribute the auto-scaling group across multiple availability zones
- B.Configure the auto-scaling group to burst into on-premises resources during spikes
- C.Increase the size of the web tier instances to handle more traffic
- D.Use a read replica of the database to distribute read traffic
Why A: Distributing the auto-scaling group across multiple Availability Zones (AZs) ensures that if one AZ fails, the web tier continues to serve traffic from the remaining AZs. This is the most critical design consideration for maintaining availability during a regional outage because it provides fault isolation at the AZ level, which is a fundamental principle of high availability in cloud architecture.
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This CV0-004 practice question is part of Courseiva's free CompTIA 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 CV0-004 exam.