AWS Interview Questions: Intermediate Level — Part 2

1. What is Auto Scaling?

Auto Scaling is an AWS service that automatically adjusts the number of EC2 instances in response to changing application demand. This ensures that you have the right number of instances running to handle the current load on your application.

Example:

You can configure an Auto Scaling group to automatically add more EC2 instances when the CPU utilization exceeds a specified threshold, and remove instances when the utilization drops below the threshold.

2. How does Elastic Load Balancing work?

Elastic Load Balancing (ELB) automatically distributes incoming application traffic across multiple targets, such as EC2 instances, containers, and IP addresses. It helps ensure that no single instance is overwhelmed, improving fault tolerance and availability.

Example:

A web application can use an ELB to distribute incoming HTTP requests across a group of EC2 instances in multiple Availability Zones.

3. Explain the different types of load balancers in AWS.

AWS offers three types of load balancers:

• Application Load Balancer (ALB): Operates at the application layer (HTTP/HTTPS), ideal for web applications.
• Network Load Balancer (NLB): Operates at the transport layer (TCP/UDP), suited for high-performance and low-latency applications.
• Classic Load Balancer (CLB): Operates at both the application and transport layers, used for applications built within the EC2-Classic network.

4. What is Amazon RDS?

Amazon Relational Database Service (RDS) is a managed database service that simplifies the setup, operation, and scaling of relational databases in the cloud. It supports multiple database engines, including MySQL, PostgreSQL, MariaDB, Oracle, and Microsoft SQL Server.

5. What are Security Groups and Network ACLs?

• Security Groups: Virtual firewalls for your EC2 instances that control inbound and outbound traffic. They operate at the instance level.
• Network ACLs (Access Control Lists): Stateless traffic filters that control inbound and outbound traffic for subnets within your VPC. They operate at the subnet level.

Example:

A security group can be configured to allow SSH access (port 22) only from a specific IP address, while a Network ACL can allow HTTP and HTTPS traffic (ports 80 and 443) for a specific subnet.

6. How do you monitor AWS resources?

You can monitor AWS resources using:

• Amazon CloudWatch: Collects and tracks metrics, monitors log files, and sets alarms.
• AWS CloudTrail: Provides governance, compliance, and operational and risk auditing by recording AWS API calls.

7. What is Amazon CloudWatch?

Amazon CloudWatch is a monitoring and observability service that provides data and actionable insights to monitor applications, understand and respond to system-wide performance changes, and optimize resource utilization.

Example:

You can use CloudWatch to create alarms that trigger notifications when the CPU utilization of an EC2 instance exceeds a defined threshold.

8. What is AWS Route 53?

AWS Route 53 is a scalable Domain Name System (DNS) web service designed to route end-user requests to internet applications by translating domain names into IP addresses.

Example:

You can use Route 53 to route traffic to different endpoints, such as Amazon S3 buckets, EC2 instances, and ELBs, based on DNS queries.

9. Explain the concept of elasticity in AWS.

Elasticity refers to the ability of AWS resources to automatically scale up or down based on demand. This ensures that the infrastructure can handle varying levels of load without over-provisioning or under-provisioning resources.

Example:

Using Auto Scaling and ELB together provides elasticity by dynamically adjusting the number of EC2 instances handling incoming traffic based on real-time demand.

10. What is the difference between RDS and DynamoDB?

• Amazon RDS: A managed relational database service supporting structured query language (SQL) databases.
• Amazon DynamoDB: A managed NoSQL database service designed for fast and predictable performance with seamless scalability.

Example:

Use RDS for applications requiring complex queries and transactions (e.g., e-commerce platforms), and DynamoDB for applications needing low-latency access to large datasets (e.g., real-time analytics).

11. What is the purpose of AWS Elastic Beanstalk?

AWS Elastic Beanstalk is an easy-to-use service for deploying and scaling web applications and services. It automatically handles the deployment, capacity provisioning, load balancing, auto-scaling, and monitoring of applications.

Example:

Developers can deploy a web application by uploading the application code, and Elastic Beanstalk handles the rest, including launching the necessary infrastructure.

12. How do you use AWS CloudTrail?

AWS CloudTrail records AWS API calls and delivers log files to an Amazon S3 bucket. It provides visibility into user activity by recording actions taken on your account.

Example:

You can use CloudTrail to track changes to your AWS resources, such as modifications to security group rules or the creation of new IAM users.

13. What is AWS Snowball?

AWS Snowball is a data transport solution that uses secure physical devices to transfer large amounts of data into and out of AWS. It helps with data migration, disaster recovery, and content distribution.

Example:

A company can use Snowball to move petabytes of data from their on-premises data center to AWS without using the internet, significantly reducing transfer times.

14. What is Amazon ElastiCache?

Amazon ElastiCache is a managed in-memory data store and cache service that supports Redis and Memcached. It helps improve the performance of applications by allowing you to retrieve data from high-throughput and low-latency in-memory caches.

Example:

A web application can use ElastiCache to store session data, reducing the load on the backend database and improving response times.

15. How do you implement multi-region deployments in AWS?

Multi-region deployments involve deploying your application across multiple AWS regions to achieve higher availability, fault tolerance, and disaster recovery. This can be done using services like Route 53 for DNS routing, RDS for cross-region read replicas, and S3 for cross-region replication.

Example:

An e-commerce application can be deployed in multiple regions using Route 53 for global traffic management, RDS for database replication, and S3 for storing and replicating product images.

In this article, we covered several intermediate-level AWS interview questions, providing detailed answers and examples to help you better understand and prepare for your AWS-related interviews.

Understanding these intermediate-level AWS concepts will provide a strong foundation for effectively utilizing AWS services in your projects. But why stop here? Enhance your expertise even further by exploring the next levels:

• AWS Interview Questions: Beginners Level — Part 1: Start from the basics and ensure your foundational knowledge is solid.
• AWS Interview Questions: Advanced Level — Part 3: Ready to tackle the most challenging AWS topics? Delve into advanced AWS interview questions and master concepts like AWS Direct Connect, serverless architecture, and disaster recovery strategies.

Keep pushing your limits and become an AWS expert!