aws interview questions and answers 2024 part 2

Amazon EC2

1. **How to fix if the root SSH key of an EC2 server was exposed?**

   • Immediately delete the exposed key from the AWS Management Console. Generate a new key pair and replace it on all instances that used the exposed key. Review access logs for unauthorized access.

2. **How to ensure security in EC2?**

   • Regularly update and patch systems, configure security groups and network access control lists (NACLs) tightly, use IAM roles for applications running on EC2, enable encryption for data at rest and in transit, and use AWS CloudTrail for auditing.

3. **What steps would you take if an EC2 instance is running out of memory?**

   • Analyze the application's memory usage, consider optimizing the code, or resize the instance to a larger type. Alternatively, add swap space or use Elastic Load Balancing to distribute the load among multiple instances.

4. **How do you recover an accidentally terminated EC2 instance?**

   • If termination protection is enabled, the instance cannot be terminated accidentally. Otherwise, you can only launch a new instance using the AMI of the terminated instance if available.

5. **How to move an EC2 instance to a different region?**

   • Create an AMI of the instance, copy the AMI to the target region, and then launch a new instance from the copied AMI in the new region.

6. **What is the process to change the instance type of a running EC2 instance?**

   • Stop the instance, change the instance type from the EC2 console, and start the instance again. Ensure the new type is compatible with your instance's configuration.

7. **How to attach an additional EBS volume to an EC2 instance?**

   • Create and attach the new EBS volume to the instance through the AWS Management Console or CLI, then format and mount the volume in the operating system.

8. **How to automate the backup process of EC2 instances?**

   • Use Amazon Data Lifecycle Manager to automate the creation, retention, and deletion of snapshots based on policies you define.

Amazon S3

9. **How to connect from Node.js to S3?**

   • Use the AWS SDK for JavaScript. Configure the SDK with your credentials and use the S3 client to interact with your bucket, such as uploading or downloading files.

10. **How to restrict public access to S3 buckets?**

    • Disable public access settings on the bucket and use bucket policies to manage access. Ensure no ACLs are granting public access.

11. **What is the method to serve static websites using S3?**

    • Enable static website hosting on the S3 bucket, upload your HTML, CSS, and JavaScript files, and set permissions to allow public read access.

12. **How to enable versioning on an S3 bucket?**

    • Turn on versioning in the bucket settings via the AWS Management Console, CLI, or SDK, allowing you to preserve, retrieve, and restore every version of every object stored in your S3 bucket.

13. **How to implement lifecycle rules in S3?**

    • Create lifecycle rules in the bucket management console specifying actions on objects (like transition to another storage class or deletion) based on age and other factors.

14. **How to encrypt files in S3?**

    • Enable default encryption on the bucket or manually set encryption on each object upload. Use AWS-managed keys (SSE-S3 or SSE-KMS) or customer-provided keys (SSE-C).

Amazon RDS

15. **How to connect to an RDS instance from a remote application?**

    • Ensure the security group associated with the RDS instance allows inbound traffic on the appropriate port from your IP or range. Use connection strings in your application with the correct username and password.

16. **How to scale an RDS instance vertically and horizontally?**

    • Vertically: Modify the instance size in RDS settings. Horizontally: Use read replicas for read-heavy database workloads.

17. **What to do if you encounter storage full on RDS?**

    • Increase the allocated storage space or enable Auto Scaling for storage. Also, consider archiving old data or cleaning up unnecessary data.

18. **How to perform a point-in-time recovery in RDS?**

    • Use the AWS console to restore the database to a specific time, using the automated backups feature.

19. **How to migrate a database from an EC2 instance to RDS?**

    • Use AWS Database Migration Service to migrate the database without downtime, ensuring the source database is fully operational during the migration.

20. **What is the procedure to change the database engine of an RDS instance?**

    • You cannot directly change the database engine. Instead, create a new R

DS instance with the desired engine and migrate the data.

Mixed Questions

21. **How to monitor the performance of AWS services?**

    • Use AWS CloudWatch to monitor metrics and logs for AWS services. Set alarms to receive notifications for any anomalies.

22. **How to implement a failover mechanism for your AWS architecture?**

    • Use Route 53 with health checks to route traffic to healthy endpoints, and set up Multi-AZ deployments in RDS and EC2.

23. **How to reduce costs in AWS?**

    • Optimize instance sizes, use Reserved Instances or Spot Instances, clean up unused resources, and leverage S3 lifecycle policies and storage classes.

24. **What security best practices should be followed in AWS?**

    • Use multi-factor authentication, least privilege principle for IAM roles, secure your data with encryption, and regularly audit configurations and access with AWS Config and IAM Access Advisor.

25. **How do you handle data transfer between different AWS regions?**

    • Use cross-region replication features in services like S3, or use the AWS Data Transfer service for other types of data.

26. **What steps would you take to troubleshoot network connectivity issues between your VPC and an internet application?**

    • Check route tables, network ACLs, security group settings, and ensure that the internet gateway is properly attached and configured.

27. **How to automate AWS resource deployments?**

    • Use AWS CloudFormation to define and provision AWS infrastructure using a declarative template.

28. **How do you ensure high availability of your AWS applications?**

    • Deploy applications across multiple Availability Zones, use services like Elastic Load Balancer and Auto Scaling groups.

29. **How can you secure data being transferred to and from AWS?**

    • Use VPN or AWS Direct Connect for secure connections and enable encryption for all data in transit using TLS/SSL.

30. **How to manage API access to AWS services?**

    • Use IAM roles and policies to control API access. Employ API Gateway for managing, monitoring, and securing APIs at scale.

These questions cover practical scenarios that could be commonly encountered while managing AWS services, providing insight into operational tasks and best practices.