AWS is a cloud computing service offered by Amazon. AWS lets you build, test, deploy and manage applications and services. All this is done via the data centers and the hardware managed by Amazon. AWS provides you a combination of Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS), and Software-as-a-Service (SaaS) offerings.
You can use AWS to create Virtual Machines which can be armed with processing power, storage capacity, and analytics along with networking and device management. AWS offers you a pay-as-you-go model, which helps to avoid upfront costs and pay based on the usage monthly.
Find the list of the top asked AWS Interview Questions and answers below.
1. What is AWS?
AWS (Amazon Web Services) is a platform to provide secure cloud services, database storage, offerings to compute power, content delivery, and other services to help business level and develop.
2. Features of AWS?
The following are the features of AWS:
- Flexibility
- Cost-effective
- Scalable and elastic
- Secure
- Experienced
3. Mention what the key components of AWS are?
The key components of AWS are
- Route 53: A DNS web service
- Simple E-mail Service: It allows sending e-mail using RESTFUL API call or via regular SMTP
- Identity and Access Management: It provides enhanced security and identity management for your AWS account
- Simple Storage Device or (S3): It is a storage device and the most widely used AWS service
- Elastic Compute Cloud (EC2): It provides on-demand computing resources for hosting applications. It is handy in case of unpredictable workloads
- Elastic Block Store (EBS): It offers persistent storage volumes that attach to EC2 to allow you to persist data past the lifespan of a single Amazon EC2 instance
- CloudWatch: To monitor AWS resources, It allows administrators to view and collect keys. Also, one can set a notification alarm in case of trouble.
4. What are the Instance purchasing options?
Amazon EC2 provides the following purchasing options to enable you to optimize your costs based on your needs:
- On-Demand Instances – Pay, by the second, for the instances that you launch.
- Savings Plans – Reduce your Amazon EC2 costs by making a commitment to a consistent amount of usage, in USD per hour, for a term of 1 or 3 years.
- Reserved Instances – Reduce your Amazon EC2 costs by making a commitment to a consistent instance configuration, including instance type and Region, for a term of 1 or 3 years.
- Spot Instances – Request unused EC2 instances, which can reduce your Amazon EC2 costs significantly.
- Dedicated Hosts – Pay for a physical host that is fully dedicated to running your instances, and bring your existing per-socket, per-core, or per-VM software licenses to reduce costs.
- Dedicated Instances – Pay, by the hour, for instances that run on single-tenant hardware.
- Capacity Reservations – Reserve capacity for your EC2 instances in a specific Availability Zone for any duration.
5. Instance Payment Options?
You can choose between three Reserved Instance payment options:
- All upfront: You receive the largest discount
- Partial upfront: You receive a lower discount.
- No upfront: You receive a smaller discount, but free-up capital to spend in other projects.
6. What is EC2?
EC2 is a Virtual Machine in the cloud on which you have OS-level control. You can run this cloud server whenever you want and can be used when you need to deploy your own servers in the cloud, similar to your on-premises servers, and when you want to have full control over the choice of hardware and the updates on the machine.
7. How to create an EC2 Instance?
There are mainly 9 steps to creating an EC2:
- Login and access to AWS services
- Choose AMI
- Choose EC2 Instance Types
- Configure Instance
- Add Storage
- Tag Instance
- Configure Security Groups
- Review Instances
- And Launch
8. What is VPC?
Amazon Virtual Private Cloud (Amazon VPC) enables you to launch AWS resources into a virtual network that you’ve defined. This virtual network closely resembles a traditional network that you’d operate in your own data center, with the benefits of using the scalable infrastructure of AWS.
9. What is Subnet?
A subnet is a logical subdivision of an IP network. The practice of dividing a network into two or more networks is called subnetting. When you create a subnet, you specify the CIDR block for the subnet, which is a subset of the VPC CIDR block. In AWS Subnet you can only use the CIDR /16 or /24.
10. What is Route Table?
A routing table contains a set of rules, called routes, that are used to determine where network traffic is directed. Each subnet in your VPC must be associated with a routing table; the table controls the routing for the subnet. A subnet can only be associated with one route table at a time, but you can associate multiple subnets with the same route table.
11. What is an Internet Gateway?
Internet Gateway allows the communication between instance’s VPC to the internet.
12. What is Elastic IP?
An Elastic IP address is a public IPv4 address, which is reachable from the internet. If your instance does not have a public IPv4 address, you can associate an Elastic IP address with your instance to enable communication with the internet.
13. How to create a VPC?
- First login to Aws Account
- Then Click on “VPC”.
- Then click on “Create a VPC” and enter name of the VPC
- Then click on “subnet” enter your name and give the range of your VPC.
- Then click on “IGW” and attach it to your VPC.
- Then click on “Route table” then attach each subnet to its particular route table.
- Then click on “Elastic IP” and add it to the private VPC.
- Then attach your VPC to EC2 instance.
14. What is VPC Peering?
Aws enables you to launch AWS resources into a virtual network that you are defined. A VPC peering connection is a networking between two or multiple VPCs that enables you to traffic between them you can access any instance via VPC peering.
15. What is RDS?
Amazon Relational Database Service (Amazon RDS) is a web service that makes it easier to set up, operate, and scale a relational database in the AWS Cloud. It provides cost-efficient, resizable capacity for an industry-standard relational database and manages common database administration tasks.
16. What is EFS?
Amazon Elastic File System (Amazon EFS) provides a simple, serverless, set-and-forget elastic file system for use with AWS Cloud services and on-premises resources. It is built to scale on-demand to petabytes without disrupting applications, growing and shrinking automatically as you add and remove files, eliminating the need to provision and manage capacity to accommodate growth. Amazon EFS has a simple web services interface that allows you to create and configure file systems quickly and easily. The service manages all the file storage infrastructure for you, meaning that you can avoid the complexity of deploying, patching, and maintaining complex file system configurations.
17. What is Cloud Watch?
Amazon CloudWatch is a monitoring and management service that provides data and actionable insights for AWS, hybrid, and on-premises applications and infrastructure resources. You can collect and access all your performance and operational data in the form of logs and metrics from a single platform rather than monitoring them in silos (server, network, or database). CloudWatch enables you to monitor your complete stack (applications, infrastructure, and services) and uses alarms, logs, and events data to take automated actions and reduce mean time to resolution (MTTR). This frees up important resources and allows you to focus on building applications and business value.
18. What is DNS?
The Domain Name System (DNS) is the phonebook of the Internet. Humans access information online through domain names, like nytimes.com or espn.com. Web browsers interact through Internet Protocol (IP) addresses. DNS translates domain names to IP addresses so browsers can load Internet resources.
Each device connected to the Internet has a unique IP address that other machines use to find the device. DNS servers eliminate the need for humans to memorize IP addresses such as 192.168.1.1 (in IPv4), or more complex newer alphanumeric IP addresses such as 2400:cb00:2048:1::c629:d7a2 (in IPv6).
19. What is Route53?
Amazon Route 53 is a highly available and scalable cloud Domain Name System (DNS) web service. It is designed to give developers and businesses an extremely reliable and cost-effective way to route end users to Internet applications by translating names like www.example.com into the numeric IP addresses like 192.168.1.1 that computers use to connect to each other. Amazon Route 53 is fully compliant with IPv6 as well.
20. What is ELB? and its type?
Elastic Load Balancing (ELB) automatically distributes incoming application traffic across multiple targets and virtual appliances in one or more Availability Zones (AZs).
- Application Load Balancer
- Classic(Gateway) Load Balancer
- Network Load Balancer
21. What is IAM?
AWS Identity and Access Management (IAM) is a web service that helps you securely control access to AWS resources. You use IAM to control who is authenticated (signed in) and authorized (has permissions) to use resources.
When you first create an AWS account, you begin with a single sign-in identity that has complete access to all AWS services and resources in the account. This identity is called the AWS account root user and is accessed by signing in with the email address and password that you used to create the account. We strongly recommend that you do not use the root user for your everyday tasks, even the administrative ones. Instead, adhere to the best practice of using the root user only to create your first IAM user. Then securely lock away the root user credentials and use them to perform only a few account and service management tasks.
22. What is Simple Storage Service (S3)?
Amazon Simple Storage Service (Amazon S3) is an object storage service that offers industry-leading scalability, data availability, security, and performance. Customers of all sizes and industries can use Amazon S3 to store and protect any amount of data for a range of use cases, such as data lakes, websites, mobile applications, backup and restore, archive, enterprise applications, IoT devices, and big data analytics. Amazon S3 provides management features so that you can optimize, organize, and configure access to your data to meet your specific business, organizational, and compliance requirements.
23. What is WorkMail?
Amazon WorkMail is a secure, managed business email and calendar service with support for existing desktop and mobile email client applications. Amazon WorkMail gives users the ability to seamlessly access their email, contacts, and calendars using the client application of their choice, including Microsoft Outlook, native iOS, and Android email applications, any client application supporting the IMAP protocol, or directly through a web browser. You can integrate Amazon WorkMail with your existing corporate directory, use email journaling to meet compliance requirements, and control both the keys that encrypt your data and the location in which your data is stored.
24. What is EBS?
Amazon Elastic Block Store (Amazon EBS) provides block-level storage volumes for use with EC2 instances. EBS volumes behave like raw, unformatted block devices. You can mount these volumes as devices on your instances. EBS volumes that are attached to an instance are exposed as storage volumes that persist independently from the life of the instance.
25. What is auto-scaling?
Auto-scaling is a function that allows you to provision and launch new instances whenever there is a demand. It allows you to automatically increase or decrease resource capacity in relation to the demand.
26. Is there any other alternative tool to log into the cloud environment other than the console?
The that can help you log into the AWS resources are:
- Putty
- AWS CLI for Linux
- AWS CLI for Windows
- AWS CLI for Windows CMD
- AWS SDK
- Eclipse
27. What are the top product categories of AWS?
The top product categories of AWS are:
- Compute
- Storage
- Database
- Networking and Content Delivery
- Analytics
- Machine Learning
- Security
- Identity
- Compliance
28. What is a Data lake?
It is a centralized data repository to store all your structured and unstructured data at any volume. The core aspect of Data lake is that you can apply various analytical tools to data, derive analytics, and uncover useful insights without structuring the data. Also, Data lake stores data coming from various sources such as business applications, mobile applications, and IoT devices.
29. What are the benefits of AWS Elastic Beanstalk?
- In a way, it is faster and simpler to deploy applications
- The auto-scaling facility of Elastic Beanstalk supports scaling applications up and down based on the demands.
- This AWS service manages application platforms by updating with the latest patches and updates.
- When they use this service, developers could achieve enough freedom to choose the type of EC2 instance, processors, etc.
Following are the few benefits of the Elastic Beanstalk:
- Easy and simple: Elastic Beanstalk enables you to manage and deploy the application easily and quickly.
- Autoscaling: Beanstalk scales up or down automatically when your application traffic increases or decreases.
- Developer productivity: Developers can easily deploy the application without any knowledge, but they need to maintain the application securely and be user-friendly.
- Cost-effective: No charge for Beanstalk. Charges are applied for the AWS service resources which you are using for your application.
- Customization: Elastic Beanstalk allows users to select the configurations of AWS services that users want to use for application development.
- Management and updates: It updates the application automatically when it changes the platform. Platform updates and infrastructure management are taken care of by AWS professionals.
30. What is AWS Lambda?
It is a serverless and event-driven computing service. It allows running codes virtually for applications without any provisioning or managing servers. Most AWS services and SaaS applications can trigger AWS Lambda. This service can execute any code volume due to its scaling properties. Also, decoupled services can be communicated through the event-driven functions of AWS Lambda.
31. How can you secure access to your S3 bucket?
S3 bucket can be secured in two ways:
- ACL (Access Control List)
ACL is used to manage the access of resources to buckets and objects. An object of each bucket is associated with ACL. It defines which AWS accounts have granted access and the type of access. When a user sends the request for a resource, then its corresponding ACL will be checked to verify whether the user has granted access to the resource or not.
When you create a bucket, then Amazon S3 creates a default ACL which provides full control over the AWS resources. - Bucket Policies
Bucket policies are only applied to the S3 buckets. Bucket policies define what actions are allowed or denied. Bucket policies are attached to the bucket, not to an S3 object but the permissions defined in the bucket policy are applied to all the objects in the S3 bucket.
32. What are key pairs?
Key Pairs are used to connect to virtual machines. The secure login credentials used to connect to virtual machines are known as Key pairs.
33. What is a redshift?
Redshift is a data warehouse product of Amazon that provides fast and powerful services; a completely manageable petabyte-scale warehouse.
34. How many buckets we can create in S3?
100 buckets.
35. What is the difference between Scalability and Elasticity?
Scalability refers to the ability of a system to increase the hardware requirements or processing nodes to tackle increasing demand.
The elasticity of a system refers to the capability of the system to add resources for improving the performance when required and returning to the original configuration when resources are not required.
This feature helps a lot in cloud computing since the resources are bought in the pay-as-you-go pricing.