Top 15- AWS EC2 interview questions and answers.
Basics and Fundamentals:
What is Amazon EC2?
- Amazon EC2 (Elastic Compute Cloud) is a web service that provides resizable compute capacity in the cloud. It allows users to rent virtual servers to run applications.
What are the different types of instances in EC2?
- EC2 offers various instance types optimized for different use cases, such as general-purpose, compute-optimized, memory-optimized, storage-optimized, etc.
Explain the difference between On-demand and Reserved instances.
- On-demand instances allow users to pay for compute capacity by the hour with no long-term commitments, while Reserved instances offer significant savings if you commit to a specific instance configuration for a period.
How can you launch EC2 instances?
- Instances can be launched via the AWS Management Console, CLI (Command Line Interface), or using SDKs (Software Development Kits).
What is an Amazon Machine Image (AMI)?
- An AMI is a pre-configured template that contains the software configuration needed to launch an EC2 instance. It includes the operating system, applications, libraries, and settings.
How do you secure an EC2 instance?
- Security can be enhanced by configuring security groups, which act as a virtual firewall, setting up Network Access Control Lists (NACLs), using IAM roles, and regularly updating patches and security groups.
Storage and Networking:
Explain Elastic Block Store (EBS) and Instance Store.
- EBS provides persistent block-level storage volumes for use with EC2 instances, while Instance Store provides temporary block-level storage that is lost when the instance is stopped or terminated.
What is a VPC (Virtual Private Cloud)?
- A VPC is a logically isolated section of the AWS Cloud where users can launch resources in a virtual network that they define.
How do you connect to an EC2 instance?
- You can connect to an EC2 instance using SSH (Secure Shell) for Linux instances or RDP (Remote Desktop Protocol) for Windows instances.
Auto Scaling and Load Balancing:
What is Auto Scaling in EC2?
- Auto Scaling allows you to automatically adjust the number of EC2 instances in response to changes in demand, ensuring optimal performance at the lowest cost.
Explain Elastic Load Balancing (ELB).
- ELB automatically distributes incoming application traffic across multiple targets, such as EC2 instances, to ensure high availability and fault tolerance.
Troubleshooting and Monitoring:
How do you troubleshoot an unreachable EC2 instance?
- Troubleshooting can involve checking security group rules, verifying network configurations, reviewing system logs, and ensuring that the instance is running.
What monitoring tools does AWS provide for EC2 instances?
- AWS offers CloudWatch, which provides monitoring and visibility into EC2 instances, including CPU utilization, network traffic, disk usage, etc.
High Availability and Disaster Recovery:
How can you achieve high availability for EC2 instances?
- High availability can be achieved by deploying instances across multiple Availability Zones (AZs), using Auto Scaling, and configuring Elastic Load Balancers.
Explain the process of creating a backup for EC2 instances.
- Backups can be created by taking snapshots of EBS volumes or by using AWS Backup, which automates the process of backing up data across multiple services.
Answers to Behavioral or Scenario-based Questions:
Can you describe a situation where you optimized EC2 instances for cost savings or performance improvements?
- (Personalized scenario-based response discussing cost optimization through instance resizing, utilization analysis, or architectural changes.)
Remember, it's not just about knowing the answers but also being able to articulate your practical experience and problem-solving skills related to EC2 instances in AWS.
I hope this helps, you!!
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