Multi-tier architecture patterns in AWS - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Architecture

intermediate

Identify the correct tier separation in a multi-tier AWS architecture

In a typical three-tier AWS architecture, which of the following correctly represents the separation of tiers?

A Presentation tier on S3 static website, Business logic tier on EC2 instances, Data tier on DynamoDB

B Presentation tier on CloudFront, Business logic tier on EC2 instances, Data tier on S3 buckets

C Presentation tier on EC2 instances, Business logic tier on Lambda functions, Data tier on RDS

D Presentation tier on RDS, Business logic tier on Lambda, Data tier on EC2 instances

💡 Hint

Think about where user interfaces, application processing, and data storage typically reside.

The presentation tier is often served by static websites on S3, the business logic runs on EC2 instances, and the data tier uses databases like DynamoDB. Option A correctly reflects this.

❓ service_behavior

intermediate

Behavior of Elastic Load Balancer in multi-tier architecture

In a multi-tier AWS architecture, what is the primary behavior of an Elastic Load Balancer (ELB) placed in front of the application tier?

A It encrypts data stored in the data tier

B It distributes incoming traffic evenly across multiple database instances

C It caches static content to reduce load on the presentation tier

D It routes user requests to multiple application servers to balance load

💡 Hint

Consider what ELB is designed to do with incoming user requests.

ELB distributes incoming user requests across multiple application servers to balance the load and improve availability. It does not interact directly with databases or caching.

❓ security

advanced

Securing data tier in multi-tier AWS architecture

Which AWS service and configuration best secures the data tier in a multi-tier architecture to ensure data encryption at rest and controlled access?

A Use S3 buckets with public read access and enable versioning

B Use DynamoDB without encryption and allow open access to all VPC subnets

C Use RDS with encryption enabled and restrict access via security groups and IAM roles

D Use EC2 instances with encrypted EBS volumes but no network restrictions

💡 Hint

Think about encryption and access control best practices for databases.

RDS with encryption enabled protects data at rest. Security groups and IAM roles restrict network and user access, securing the data tier effectively.

✅ Best Practice

advanced

Best practice for scaling the business logic tier

What is the best practice to scale the business logic tier in a multi-tier AWS architecture to handle variable traffic loads efficiently?

A Use Auto Scaling groups with CloudWatch alarms to automatically adjust EC2 instances

B Use S3 to host business logic code for automatic scaling

C Manually add more EC2 instances during peak hours and remove them after

D Deploy all business logic on a single large EC2 instance to avoid complexity

💡 Hint

Consider automation and monitoring for scaling resources.

Auto Scaling groups with CloudWatch alarms automatically adjust the number of EC2 instances based on traffic, ensuring efficient scaling without manual intervention.

🧠 Conceptual

expert

Impact of multi-tier architecture on fault tolerance

How does implementing a multi-tier architecture in AWS improve fault tolerance compared to a single-tier architecture?

A By combining all services into one tier, it reduces the number of failure points

B By isolating tiers, failure in one tier does not necessarily cause the entire system to fail

C By using a single database for all tiers, it ensures data consistency and fault tolerance

D By eliminating the need for load balancers, it reduces complexity and failure risks

💡 Hint

Think about how separating responsibilities affects system resilience.

Multi-tier architecture isolates different parts of the system. If one tier fails, others can continue working or degrade gracefully, improving fault tolerance.