AWS Services and Concepts
- What is AWS?
- AWS (Amazon Web Services) is a cloud computing platform provided by Amazon, offering a wide range of cloud services.
- What are the key components of AWS?
- Key components include EC2 (Elastic Compute Cloud), S3 (Simple Storage Service), RDS (Relational Database Service), VPC (Virtual Private Cloud), IAM (Identity and Access Management), etc.
- Explain what EC2 instances are and their types.
- EC2 (Elastic Compute Cloud) instances are virtual servers in the AWS cloud. Types include On-Demand Instances, Reserved Instances, Spot Instances, and Dedicated Instances.
- What is S3 and what are its use cases?
- S3 (Simple Storage Service) is object storage in AWS used for storing and retrieving any amount of data. Use cases include backup and restore, data archiving, web hosting, etc.
- What is an AMI in AWS?
- An AMI (Amazon Machine Image) is a template used to create virtual machines (EC2 instances) in AWS.
- Explain what a VPC is and its components.
- VPC (Virtual Private Cloud) is a virtual network dedicated to your AWS account. Components include subnets, route tables, internet gateways, NAT gateways, etc.
- What is Auto Scaling in AWS?
- Auto Scaling automatically adjusts the number of EC2 instances in a group based on traffic demand or other metrics.
- What is Elastic Load Balancing (ELB)?
- ELB automatically distributes incoming application traffic across multiple targets (such as EC2 instances) to ensure high availability and fault tolerance.
- Explain the concept of IAM in AWS.
- IAM (Identity and Access Management) manages access to AWS services and resources securely. It involves users, groups, roles, and policies.
- What is CloudFormation in AWS?
- CloudFormation is an AWS service that allows you to model and set up your AWS resources so that you can deploy and update them in an orderly and predictable fashion.
DevOps Concepts and Tools
- What is DevOps?
- DevOps is a set of practices that combines software development (Dev) and IT operations (Ops) to shorten the development lifecycle and deliver software faster and more reliably.
- Explain the CI/CD pipeline.
- CI (Continuous Integration) is the practice of automating the integration of code changes from multiple contributors into a single software project. CD (Continuous Delivery/Deployment) extends CI by automating the release of applications to infrastructure.
- Name some popular CI/CD tools and explain their roles.
- Examples include Jenkins (automation server), GitLab CI/CD (integrated CI/CD tool), Travis CI (CI service for GitHub projects), CircleCI (CI/CD platform).
- What is Docker?
- Docker is a platform for developing, shipping, and running applications using containerization.
- What is Kubernetes?
- Kubernetes is an open-source container orchestration platform for automating the deployment, scaling, and management of containerized applications.
- Explain the difference between Docker and Kubernetes.
- Docker is a containerization platform for packaging applications and their dependencies, while Kubernetes is a container orchestration platform for automating the deployment and management of containers.
- What is Infrastructure as Code (IaC)?
- IaC is the practice of managing and provisioning computing infrastructure through machine-readable script files, rather than physical hardware configuration.
- Name some IaC tools.
- Examples include AWS CloudFormation, Terraform, Ansible, Chef, Puppet.
- What are microservices?
- Microservices is an architectural style that structures an application as a collection of loosely coupled services, which are independently deployable and scalable.
- Explain blue-green deployment.
- Blue-green deployment is a technique that reduces downtime and risk by running two identical production environments, with one serving live traffic (blue) while the other (green) is staged with new changes. Traffic is switched between the environments as needed.
Networking and Security
- What is a subnet?
- A subnet is a segmented portion of a larger network, typically within a VPC, that allows you to group resources and control network traffic flow.
- What is a Security Group in AWS?
- A Security Group acts as a virtual firewall for your EC2 instances to control inbound and outbound traffic.
- Explain the difference between TCP and UDP.
- TCP (Transmission Control Protocol) is connection-oriented and ensures reliable data delivery, while UDP (User Datagram Protocol) is connectionless and does not guarantee delivery.
- What is SSL/TLS?
- SSL (Secure Sockets Layer) and its successor TLS (Transport Layer Security) are cryptographic protocols designed to provide secure communication over a computer network.
- What is encryption?
- Encryption is the process of converting plaintext into ciphertext to secure sensitive data.
Monitoring and Logging
- What is CloudWatch?
- CloudWatch is a monitoring and management service in AWS that provides data and actionable insights for AWS cloud resources and applications.
- How can you monitor EC2 instances using CloudWatch?
- You can monitor EC2 instances by collecting and tracking metrics (such as CPU utilization, disk usage) and setting alarms based on thresholds.
- Explain the role of CloudTrail in AWS.
- CloudTrail is a service that logs AWS API calls and events for your account, providing visibility into user activity.
- What is ELK Stack?
- ELK Stack (Elasticsearch, Logstash, Kibana) is a set of tools for centralized logging and log analysis.
- What is Prometheus?
- Prometheus is an open-source monitoring and alerting toolkit originally built at SoundCloud for monitoring metrics and generating alerts.
Database and Storage
- What is RDS in AWS?
- RDS (Relational Database Service) is a managed database service that makes it easier to set up, operate, and scale a relational database in the cloud.
- What is DynamoDB?
- DynamoDB is a fully managed NoSQL database service provided by AWS that offers seamless scalability and low-latency performance.
- What is EBS in AWS?
- EBS (Elastic Block Store) provides block-level storage volumes for use with EC2 instances.
- What is SNS in AWS?
- SNS (Simple Notification Service) is a fully managed messaging service for both application-to-application and application-to-person communication.
- Explain the difference between S3 and EBS.
- S3 is object storage for files and other unstructured data, while EBS provides block-level storage volumes that can be attached to EC2 instances.
Security and Compliance
- What is IAM Policy?
- An IAM (Identity and Access Management) policy is a document that defines permissions for AWS entities (users, groups, roles).
- How can you secure your AWS account?
- By using IAM to manage users and their permissions, enabling MFA (Multi-Factor Authentication), configuring security groups and network ACLs, encrypting data at rest and in transit, and monitoring account activity.
- What is AWS KMS?
- AWS KMS (Key Management Service) is a managed service that makes it easy for you to create and control the encryption keys used to encrypt your data.
- What is a DDoS attack?
- A DDoS (Distributed Denial of Service) attack is a malicious attempt to disrupt normal traffic to a targeted server, service, or network by overwhelming it with a flood of internet traffic.
- Explain the Shared Responsibility Model in AWS.
- The Shared Responsibility Model delineates security responsibilities between AWS and the customer. AWS is responsible for the security of the cloud (hardware, software, networking), while the customer is responsible for security in the cloud (data, applications, identity).
Troubleshooting and Performance Optimization
- How can you troubleshoot performance issues in AWS?
- By monitoring metrics (CPU, memory, disk I/O), analyzing logs, reviewing CloudWatch alarms, using performance testing tools, and optimizing application code and infrastructure.
- What is CloudFormation stack?
- A CloudFormation stack is a collection of AWS resources that you can manage as a single unit.
- Explain the difference between horizontal and vertical scaling.
- Horizontal scaling increases the number of instances of a service, while vertical scaling increases the capacity of each individual instance.
- What is latency? How can you reduce it?
- Latency is the time it takes for data to travel from its source to its destination. You can reduce latency by optimizing network routes, using content delivery networks (CDNs), and employing caching mechanisms.
- How can you improve the performance of a database in AWS?
- By optimizing queries, indexing, and schema design; choosing the appropriate instance type and storage options; using read replicas; and implementing caching strategies.
Automation and Scripting
- What is scripting? Name some scripting languages used in DevOps.
- Scripting is the process of writing and executing scripts to automate tasks. Examples of scripting languages include Bash, Python, PowerShell, and Ruby.
- How can you automate deployment in AWS?
- By using CI/CD pipelines with tools like Jenkins, GitLab CI/CD, AWS CodePipeline, and AWS CodeDeploy.
- Explain the role of AWS Lambda in automation.
- AWS Lambda is a serverless compute service that lets you run code without provisioning or managing servers. It is often used for event-driven automation tasks.
- What is AWS CLI? How can it be useful in DevOps?
- AWS CLI (Command Line Interface) is a unified tool to manage AWS services from the command line. It can be used to automate tasks, manage resources, and integrate with scripts.
- What are serverless architectures?
- Serverless architectures refer to applications that significantly depend on third-party services (Backend as a Service or BaaS) or on custom code run in ephemeral containers (Function as a Service or FaaS), rather than on traditional server-based infrastructure.
These questions cover a broad spectrum of topics that are essential for a fresher AWS DevOps engineer. Be sure to review these concepts thoroughly and practice explaining them concisely for your interview preparation.