AWS Interview Questions and Answers

1. What is AWS?

AWS is the abbreviation of Amazon Web Services. It is a cloud service from Amazon that offers services that takes the form of building blocks. These building blocks can be applied to build and deploy any type of application in the cloud.

AWS is formed so as to function with each other. It results in applications which are sophisticated and profoundly scalable. 

2. Explain what is S3?

S3 refers to Simple Storage Service. You can apply the S3 interface to store and retrieve any sum of data at any time and from any place on the web. The payment model is “pay as you go” for S3. 

3. How is buffer used in AWS?

Buffer  is used to make the system more robust and manage traffic by synchronizing different components.The component processes the requests in an imbalanced manner. With the help of buffer, the components function at the same speed for quicker services and will also be balanced.

4. Explain the key components of AWS?

  1. Route 53
  2. Identity and Access Management
  3. Simple E-mail serve
  4. Simple Storage Device
  5. Elastic Block Store
  6. Elastic Compute Cloud
  7. Cloud watch

5. What is AMI?

AMI is the abbreviation of Amazon Machine Image. It is a template that offers the information of the operating system, server, applications etc. to run an instance that is the replica of the AMI running in the cloud by taking the role of a virtual server. 

An instance can be initiated from as many various AMIs according to the requirement. 

6. What is auto-scaling?

It is one of the great features of AWS.It supervises your applications and automatically adjusts capacity to keep up steady, predictable performance in the economic cost. With the help of AWS Auto Scaling, it’s simple to setup application scaling for several resources across multiple services in minutes. 

7. Distinguish between scalability and flexibility?

Scalability: It is the ability of any scheme to augment the tasks on its hardware resources. This is for the purpose of holding the inconsistency in command. 

Flexibility: Flexibility is the aptitude of a schema that boosts the task on the hardware property. 

AWS offers various configuration solutions for AWS scalability, flexibility, management and availability.

8. Is an internet gateway required to use peering connections?

There is no requirement of internet gateway to apply virtual private cloud peering connections.

9. What is RedShift?

Being a data warehouse product, Amazon RedShift is a quick and powerful, completely managed, petabyte scale data warehouse service in the cloud. 

10. What is Geo Restriction on cloud front?

Also termed as geo-blocking, Geo Restriction can be applied to restrict or block the users in a specific geographic location from accessing the content that is being distributed with the help of a CloudFront web distribution. 

11. What is SimpleDB?

Amazon Simple Database Service (SimpleDB) is also called as a key value data store. It is extensively available and flexible non-relational database that lets developers to request and store data. This is done with minimal database management and administrative responsibility. 

12. Is one Elastic IP address enough for every instance that I have running?

Every instance has its own private and public address. The private address is connected exclusively with the instance and is returned to Amazon EC2 only at the time of being stopped or terminated. In the same way, the public address is connected exclusively with the instance until it is stopped or terminated. But this can be replaced by the unique Elastic IP address. Its specialty is that it stays with the instance as long as the user doesn’t remove it manually. However when you are hosting multiple websites on your EC2 server, you may need more than one Elastic IP address. 

13. What are the best practices for Security in Amazon EC2?

There are various best practices to secure Amazon EC2. Some of them are:

  • Apply AWS Identity and Access Management to manage access to your AWS resources. 
  • Restrict access by only letting trusted hosts or networks to reach ports on your instance.
  • Go through the rules in your security groups in a diligent manner frequently 
  • Open only permissions that you need
  • Disable password-based logins for instances initiated from your AMI. Passwords can be identified or cracked and pave way to security risk. 

14. How will you access the data on EBS in AWS ?

Elastic block storage offers long-lasting, highly available and high performance block level storage that can be associated to a running EC2 instance. The storage can be eventually formatted and mounted as  a file system. The raw storage can be reached directly too. 

15. Differentiate between vertical and horizontal scaling in AWS.

The manner in which you add compute resources to your infrastructure is the major difference between vertical and horizontal scaling. More power is added to the available machine in vertical scaling while extra resources are added into the system in horizontal scaling. There is also the addition of more machines into the network in such a way that the processing and workload is shared among multiple devices.

16. What is the total number of buckets that can be created in AWS by default ?

100 buckets can be formed in each of the AWS accounts. If more buckets are needed, raise the bucket limit by submitting a service limit increase.

17. What are the possible connection issues you encounter when connecting to an EC2 instance?

  • Unprotected private key file
  • Connection timed out
  • Server refused key
  • No supported authentication method present
  • Host key not found,permission denied.
  • User key not recognized by the server, permission denied.

18. What happens when you launch instances in Amazon VPC ?

Each instance contains a default IP address once the instance is initiated in Amazon VPC. This strategy is regarded ideal when you should link cloud resources with the data centers. 

19. Is it possible to scale an Amazon instance vertically? How?

It is possible. You have to simply stop the server and then change the instance type. You should again start the server.

20. What is DynamoDB?

DynamoDB is the solution when you need a fast and flexible NoSQL database that has a flexible data model and dependable performance. 

21. What are the different types of instances?

Following are the types of instances,

  • General purpose
  • Storage Optimized
  • Computer Optimized
  • Accelerated Computing
  • Memory Optimized

22. What are policies and what are the types of policies?

Policies are permissions that you can associate to the users that you build. These policies will consist of that specific access that you have given to the users that you have created. The two types of policies are:

  • Managed policies
  • Inline policies

23. What is a snowball?

Snowball is a data transport solution that boosts moving terabyte to petabytes of data into and out of AWS services using storage devices framed to be secure for physical transport. With the help of Snowball you can remove challenges that can be faced with large-scale data transfers comprising high network costs, security concerns and long transfer times. 

24. How can you convert a public subnet to private subnet?

Eliminate IGW and add NAT Gateway, connect subnet in Private route table. 

25.What are the alternative tools available to log into a cloud environment other than console?

Putty, AWS CLI for Linux, AWS CLI for Windows, and AWS CLI for Windows CMD, AWS SDK, and Eclipse are the tools that can help the user to log into AWS cloud resources.

26.Explain the native AWS Security logging options?

There are two AWS services such as AWS CloudTrail, and AWS Config. AWS CloudTrail provides a history of the AWS API calls for all accounts and allows the user to perform security analysis, compliance auditing, and resource change tracking. It enables the user to configure the service to send notifications through AWS SNS while new logs are delivered.

AWS Config helps the user to understand the configuration changes that are happening in the cloud environment. It provides an AWS inventory that contains configuration change notification, configuration history, and relationships between AWS resources. It will be configured to send information through AWS SNS while new logs are delivered.

27.Define DDoS attacks and how to minimize them?

DDoS attack is one of the cyber attacks that the frauds access from a particular website and generates multiple sessions which cause normal user can’t access the services of a website. The native tools like AWS Shield, AWS WAF, Amazon Route53, Amazon CloudFront, VPC, and ELB are used to deny the DDoS attacks on AWS services.

28.Explain the various types of AWS Virtualization

There are three major virtualizations in AWS such as Hardware Virtual Machine (HVM), Paravirtualization (PV), and Paravirtualization on HVM.

Hardware Virtual Machine is fully virtualized hardware that all the virtual machines are acting separate from each other and it boots by executing a master boot record in the root block device of the picture of users.

Paravirtualization – GRUB is the bootloader where the boots the PV AMIs and it chain loads the kernel functionalities in the menu

Paravirtualization on HVM – It assists the operating systems to take advantage of storage and network I/O available via host.

29.List out the AWS services that are non-region-specific

Non-region-specific AWS Services are IAM, Web Application Firewall, Route 53, and CloudFront.

30.List some of the EC2 instances as per the costs?

There are three types of EC2 instances as On-demand instances used for a short time, Spot Instance that is less expensive and can buy through the bidding method, and Reserved instances used for a year or more.

31.What are the popular types of AMI designs?

There are many AMI designs available but the popular among them are fully baked AMI, Just enough baked AMI (JeOS AMI), and Hybrid AMI.

32.How to connect multiple sites to VPC?

AWS VPN CloudHub provides features for secure communications when connecting multiple sites to VPC.

33.List out some security products and features of VPC.

Security Groups: It acts like a firewall for the EC2 instances along with controlling the inbound and outbound traffic at the instance level.

Network Access Control Lists: It acts as a firewall for the subnets along with services that control inbound and outbound traffic at the subnet level.

Flow Logs: These are capturing the inbound and outbound traffic from the network instances of the user VPC.

34.How to monitor Amazon VPC?

Amazon VPC can monitor using VPC Flow Logs, CloudWatch, and CloudWatch Logs

35.How to add an existing instance to a new Auto Scaling Group?

Following are the steps to add an existing instance to a new auto-scaling group.

Step 1: Open EC2 Console

Step 2: Choose the instance under the instance’s option

Step 3: Select Actions -> Instance Settings -> Attach to Auto Scaling Group

Step 4: Choose a new Auto Scaling Group

Step 5: Attach the selected group to the instance

Step 6: Update the instance if required

Step 7: Once complete the process, an existing instance can be added successfully to a new auto-scaling group.

36.What are factors to be considered when migrating to AWS?

The following things to be considered when shifting to Amazon Web Services:

Operational Costs including the infrastructure cost, match demand and supply, transparency, etc.

Workforce productivity

Cost Avoidance

Operational Resilience

Business Agility

37.Define RPO and RTO

RTO is a Recovery Time Objective that means the maximum time the business is interested to wait for a recovery to finish in the wake of an outage. RPO is a Recovery Point Objective that means the maximum amount of data loss the company is willing to accept as measured in the given time.

38.List the elements of an AWS CloudFormation template

AWS CloudFormation templates are JSON formatted text files or YAML that are framed by five major elements as Template Parameters, Output Values, Data Tables, Resources, and File Format Version.

39.What is the difference between AWS CloudFormation and AWS Elastic Beanstalk?

AWS CloudFormation provides the provision and defines all the infrastructure resources that are in the user’s cloud environment. It supports the infrastructure needs of different types of applications like traditional, legacy, and existing enterprise applications.

AWS Elastic Beanstalk offers the platform to make deployment and execution easy in the cloud environment. It combines with the developer tools to assist the user to manage the lifecycle of an application in the cloud.

40.How to automate EC2 backup by using EBS?

Obtain the list of instances and connect to AWS using API to list the Amazon EBS volumes that are connected locally to the instances. Then list the snapshots of every volume to assign a retention period of the snapshot and create a snapshot of each volume. Finally, ensure to remove the snapshot if it was older than the retention period.

41.How can AWS IAM help the business?

AWS IAM enables the business in the following two ways

Manage IAM users and their access as it provides secure resource access to multiple users.

Manage access for federated users as it allows the business to provide secure access to resources through AWS account to applications and employees without generating individual roles.

42.What is the difference between a Hosted Zone and Domain?

Hosted Zone is a container that contains information about how the user wants to route traffic on the internet for a particular domain.

Domain is a collection of data describing a self-contained technical unit and administration.

43.How Amazon Route 53 offers high availability and low latency?

Following are the ways that Amazon Route 53 offers the resources

Globally Distributed Servers: Amazon is an international service and continuously has DNS service worldwide. Any customer generating a query from any part of the world and wants to reach a DNS server local to them provides low latency.

Dependency: Route 53 offers a high level of dependability required by complicated applications.

Optimal Locations: Route 53 utilizes a global anycast network to respond to the queries from optimal position automatically.

44.What are the various types of load balancers in AWS and what are the uses of them?

Elastic Load Balancing of AWS supports three different load balancers such as Application Load Balancer, Network Load Balancer, and Classic Load Balancer.

Application Load Balancer can be used when the user requires flexible application management and TLS termination.

Network Load Balancer can be used when users require extreme performance and static IPs for the applications.

We hope the given AWS Interview Questions and Answers help you to ace the interview easily as we carefully framed as per the requirement of industries. Learn AWS Training in Chennai at SLA to gain expertise in cloud computing with Amazon Web Services. Stay tuned with our updates on AWS Interview Questions and Answers.

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