AWS basics Interview Questions And Answers

Amazon Web Services, commonly known as AWS, is the leading cloud provider from Amazon that provides over 170 AWS services as building blocks to the developers. Developers can use these building blocks to create and deploy applications anywhere and anytime because the services/building blocks work together.

Many firms, either small or enormous, get benefits from using AWS as it helps them create their custom cloud-based solutions. With AWS, you can choose different servers according to your need, which can work in several different configurations. AWS can help in game development, data processing, warehousing, achievement, and more.

Advantages Of AWS

One of the vital AWS interview questions you must know is why you need AWS. So, why does anyone use AWS? Below are some primary advantages of AWS:

Global Availability Of AWS

AWS has almost 20 global data centres that users can operate at multiple availability zones.

Scalability and Elasticity of AWS

AWS provides organizations with unlimited scalability and flexibility, which most traditional data centres can’t offer. There is an Auto Scaling service, so the application is always available. Moreover, users can add more services and use them within a few minutes.

If an organisation uses fewer resources and doesn’t need the rest of the services, AWS will shrink as per the requirements. Therefore, AWS can upsize and downsize the resources as the organisations need.

AWS-Little Investment/cost-efficient

Organisations can save excess expenditures on software and hardware with the help of AWS cloud-related services. Moreover, there is no need for a physical data centre which protects the operating costs.

AWS-Easy To Use

Organisations can use AWS quickly and securely as users can update and access the data anywhere and anytime.

AWS-Security

AWS security is one of the essential benefits that you must know for AWS interview questions. AWS provides great security tools to organisations which they can quickly implement into their individual IT environments for security.

Moreover, it efficiently manages the data. AWS keeps it well hidden and allows access to the data at the same time. AWS constantly monitors the data centres distributed worldwide to save data loss permanently. The different layers of data surveillance for data security, in a nutshell, are as follows:

• Data protection
• Identity and access management
• Infrastructure protection
• Threat detection and continuous monitoring
• Compliance and data privacy

1 . What is Cloud Computing in AWS?

Cloud computing provides access to IT resources such as computing power, applications, and storage to users as per their demands. Here, users do not need to maintain their physical resources on their premises. In cloud computing, you can pay only for the resources you have used, so there are no investment costs. This service provides greater flexibility and scaling on resources according to your changing workloads.

2 . What are the featured services of AWS?

The Key Components of AWS are:  

• Elastic compute cloud( EC2): It acts as an on-demand computing resource for hosting applications. EC2 is very helpful in times of uncertain workloads. 
• Route 53: It’s a DNS web service.
• Simple Storage Device S3: It is a widely used storage device service in AWS Identity and Access Management.
• Elastic Block Store: It allows you to store constant volumes of data which is integrated with EC2 and enables you to persist data. 
• Cloud watch: It allows you to watch the critical areas of the AWS with which you can even set a reminder for troubleshooting.
• Simple Email Service: It allows you to send emails with the help of regular SMTP or by using a restful API call.

3 . What are the top product categories of AWS?

The top product categories of AWS are:

1. Compute
2. Storage
3. Database
4. Networking and Content Delivery
5. Analytics
6. Machine Learning
7. Security
8. Identity
9. Compliance

4 . What is a Data lake in AWS?

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.

5 . What is Serverless Computing?

AWS offers a serverless computing facility to run codes and manage data and applications without managing servers. Serverless computing eliminates infrastructure management tasks like capacity provisioning, patching, etc. It reduces the operating costs significantly. As this technology scales in response to the demands for resources automatically, it ensures quick service to users.

6 . What is Amazon EC2?

Amazon EC2 is known as Amazon Elastic Cloud Computing Platform. It provides a robust computing platform to handle any workload with the latest processors, storage, Operating Systems, and networking capabilities. It simplifies the computing process for developers. And this service reduces time by allowing quick scaling as per the requirements.

7 . What is Amazon EC2 Auto Scaling?

This AWS service automatically adds or removes EC2 instances as per the changing demands in workloads. Also, this service detects the unhealthy EC2 instances in the cloud infrastructure and replaces them with new instances, consequently. In this service, scaling is achieved in dynamic scaling and Predictive scaling. They can be used separately as well as together to manage the workloads.

8 . What is fleet management in Amazon EC2 Auto Scaling?

Amazon EC2 auto-scaling service continuously monitors the health of Amazon EC2 instances and other applications. When EC2 auto-scaling identifies unhealthy instances, it automatically replaces the unhealthy EC2 instances with new EC2 instances. Also, this service ensures the seamless running of applications and balances EC2 instances across the zones in the cloud.

9 . What is Amazon CloudFront?

Amazon CloudFront is known as the Content Delivery Network (CDN) service. This service provides high security and performance and is a developer-friendly tool. Amazon CloudFront uses a global network with 310+ Points of Presence (PoPs) across the globe, which helps to reduce latency effectively. And this service uses automated mapping and intelligent routing mechanisms to reduce latency. Amazon CloudFront secures data by applying traffic encryption and controlling access to data.

10 . What is Amazon VPC?

Amazon VPC is known as Amazon Virtual Private Cloud (VPC), allowing you to control your virtual private cloud. Using this service, you can design your VPC right from resource placement and connectivity to security. And you can add Amazon EC2 instances and Amazon Relational Database Service (RDS) instances according to your needs. Also, you can define the communication between other VPCs, regions, and availability zones in the cloud.

11 . What is Amazon SQS?

Amazon Simple Queuing Service (SQS) is a fully managed message queuing service. Using this service, you can send, receive and store any quantity of messages between the applications. This service helps to reduce complexity and eliminate administrative overhead. In addition to that, it provides high protection to messages through the encryption method and delivers them to destinations without losing any message.

12 . What are the two types of queues in SQS?

There are two types of queues known

AWS-Standard Queues: It is a default queue type. It provides an unlimited number of transactions per second and at least one message delivery option. 

AWS-FIFO Queues: FIFO queues are designed to ensure that the order of messages received and sent is strictly preserved as in the exact order that they sent.

13 . What is Amazon DynamoDB?

Amazon DynamoDB is a fully managed, serverless, key-value No SQL database service. This service has many essential features such as built-in security, in-memory caching, continuous back-ups, data export tools, and automated multi-region replication. Mainly, you can run high-performance applications at any scale using this service. For instance, it extensively supports internet-scale applications that require high concurrency and connections for many users with millions of requests per second.

14 . What is Amazon S3 Glacier?

It is a storage class built for data archiving, which helps retrieve data with high flexibility and performance. So, data can be accessed faster in milliseconds, and S3 Glacier offers a low-cost service. There are three S3 glacier storage classes – Glacier instant retrieval storage, S3 Glacier flexible retrieval, and S3 Glacier deep archive.

15 . What is Amazon Redshift?

Amazon Redshift helps analyze data stored in data warehouses, databases, and data lakes using Machine Learning (ML) and AWS-designed hardware. It uses SQL to analyze structured and semi-structured data to yield the best performance from the analysis. This service automatically creates, trains, and deploys Machine Learning models to create predictive insights.

16 . What are Elastic Load Balancing (ELB) and its types?

Elastic Load Balancing (ELB) automatically directs incoming application traffic to various destinations and virtual appliances. In fact, the destinations and virtual appliances may be in one or more availability zones. In this service, you can secure your applications using tools such as integrated certificate management, SSL/TLS decryption methods, and user authentication.

There are three types of load balancers such as Application Load Balancer, Gateway Load Balancer, and Network Load Balancer.

17 . What are sticky sessions in ELB?

A sticky session is also known as session affinity. During sticky sessions, load balancers connect a user’s session with a specific target. So, all the user’s requests during that session will be directed to the same target. It will provide a continuous experience to users. Here, the cookie AWSELB is used to define the sticky session duration to the instance.

18 . What is AWS Elastic Beanstalk?

This AWS service helps deploy and manage applications in the cloud quickly and easily. Here, developers need to upload the codes; after that, Elastic Beanstalk will manage other requirements automatically. Simply put, Elastic Beanstalk manages right from capacity provisioning, auto-scaling, load balancing up to application health monitoring.

19 . What are the benefits of AWS Elastic Beanstalk?

1. In a way, it is faster and simpler to deploy applications
2. The auto-scaling facility of Elastic Beanstalk supports scaling applications up and down based on the demands.
   
3. This AWS service manages application platforms by updating with the latest patches and updates.
   
4. 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:

1. Easy and simple: Elastic Beanstalk enables you to manage and deploy the application easily and quickly.
   
2. Autoscaling: Beanstalk scales up or down automatically when your application traffic increases or decreases.
   
3. Developer productivity: Developers can easily deploy the application without any knowledge, but they need to maintain the application securely and be user-friendly.
   
4. Cost-effective: No charge for Beanstalk. Charges are applied for the AWS service resources which you are using for your application.
   
5. Customization: Elastic Beanstalk allows users to select the configurations of AWS services that users want to use for application development.
   
6. 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.

20 . What is Amazon CloudWatch?

Amazon CloudWatch is a monitoring service that would help IT professionals, extensively by providing actionable insights. The tool provides complete visibility on AWS resources and applications running on AWS and on-premises. In addition, it tracks the status of applications, which would help to apply suitable response actions and optimize the performance of applications.

21 . What is AWS Snowball?

AWS Snowball is an edge computing and storage service. There are two features available in this service: Snowball edge storage optimized devices and Snowball edge compute optimized devices. The snowball storage devices offer block storage and Amazon S3 object storage. Snowball edge computing devices provide 52 vCPUs and an optional GPU, and it is suitable for handling advanced Machine Learning and full-motion video analysis.  

Classic Load Balancer: Classic load balancer is designed to make routing decisions either at the application layer or transport layer. It requires a fixed relationship between the container instance port and the load balancer port.

22 . What is AWS CloudTrail?

This AWS service monitors user activities on AWS infrastructure and records their activities. And this service identifies suspicious activities on AWS resources through CloudTrail insights and Amazon EventBridge features. So, you can get reasonable control over your resources and response activities. In addition to that, it analyses the log files with Amazon Athena.

23 . What is Amazon ElastiCache?

It is an in-memory caching service. It acts as a data store that can be used as a database, cache, message broker, and queue. This caching service accelerates the performance of applications and databases. For instance, you can access data in microseconds using this caching service. Not only that, it helps to reduce the load on the backend database.

24 . 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.

25 . What is the difference between Data Warehouse and Data Lake?

26 . What is the importance of buffers in AWS?

A buffer helps to integrate and synchronize various components in AWS and helps to maintain equilibrium by linking multiple apparatus to deliver quick services at a uniform rate.

27 . What are key-pairs?

Key Pairs are used to connect to the virtual machines. The secure login credentials used to connect to virtual machines are known as Key pairs. Key-pairs in AWS is the commonly asked AWS interview question.

28 . What are the types of volumes in EBS?

Various types of Volumes in EBS are listed below.

• General-purpose
• Magnetic
• Provisioned IOPS
• Cold HDD
• Throughput optimized

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

One Hundred(100) buckets can be created in each AWS account by default. We can also increase the number of buckets by submitting a request form to Amazon.

30 . What is an AMI?

Amazon Machine Image contains various software configurations, block device mapping for allocating volumes to the virtual machine and launch permissions.

31 . What is an EIP?

An elastic IP address is useful for dynamic cloud computing where we can stop and restart the instances multiple times.

32 . List various parameters involved in S3 pricing.

The parameters determining the S3 pricing are listed below.

• Data transfer
• Storage utilised
• Transfer acceleration
• Storage management
• Number of requests

33 . What is the prerequisite for Cross-region replication in S3?

The source and destination buckets should be in different regions and versioning must be enabled at both the source and destination. We also have a set of Python Interview Questions that are asked frequently to the freshers. You can find those questions by clicking the preceding link.

Explain Policies.

Policies refer to permissions attached to the created users to access AWS accounts.

Types of Policies

• Inline policies
• Managed policies

34 . What are the Edge locations?

Edge Location refers to the location where the contents are cached and can be useful when users access the content. If the searched content is unavailable in edge locations, the content will be created from an origin location and a copy of it will be saved in the edge locations.

35 . What is Cross Region Replication?

Cross Region Replication is a service available in aws that enables to replicate the data from one bucket to another bucket which could be in a same or different region. It provides asynchronous copying of objects, i.e., objects are not copied immediately.

36 . What are Regions and Availability Zones in aws?

Regions: A region is a geographical area which consists of 2 or more availability zones. A region is a collection of data centers which are completely isolated from other regions.

Availability zones: An Availability zone is a data center that can be somewhere in the country or city. Data center can have multiple servers, switches, firewalls, and load balancing. The things through which you can interact with the cloud reside inside the Data center.

37 . Difference between Stopping and Terminating the instances?

Stopping: You can stop an EC2 instance and stopping an instance means shutting down the instance. Its corresponding EBS volume is still attached to an EC2 instance, so you can restart the instance as well.

Terminating: You can also terminate the EC2 instance and terminating an instance means you are removing the instance from your AWS account. When you terminate an instance, then its corresponding EBS is also removed. Due to this reason, you cannot restart the EC2 instance.

38 . What are NAT Gateways?

NAT stands for Network Address Translation. It is an aws service that enables to connect an EC2 instance in a private subnet to the internet or other AWS services.

39 . How can you control the security of your VPC?

You can control the security to your VPC in two ways:

• Security Groups
  It acts as a virtual firewall for associated EC2 instances that control both inbound and outbound traffic at the instance level. 
• Network access control lists (NACL)
  It acts as a firewall for associated subnets that control both inbound and outbound traffic at the subnet level.

40 . What is SNS?

SNS stands for Simple Notification Service. It is a web service that provides highly scalable, cost-effective, and flexible capability to publish messages from an application and sends them to other applications. It is a way of sending messages.

41 . What are the different types of routing policies in route53?

Following are the different types of routing policies in route53:

• Simple Routing Policy
  • Simple Routing Policy is a simple round-robin policy which is applied to a single resource doing the function for the domain. For example, a web server is sending the content to a website where the web server is a single resource.
  • It responds to DNS queries based on the values present in the resource.
• Weighted Routing Policy
  • Weighted Routing Policy allows you to route the traffic to different resources in specific proportions. For example, 75% in one server, and 25% in another server.
  • Weights can be assigned in the range from 0 to 255.
  • Weight Routing policy is applied when there are multiple resources accessing the same function. For example, web servers accessing the same website. Each web server will be given a unique weight number.
  • Weighted Routing Policy associates the multiple resources to a single DNS name.
• Latency-based Routing Policy
  • Latent-based Routing Policy allows Route53 to respond to the DNS query at which data center gives the lowest latency.
  • Latency-based Routing policy is used when there are multiple resources accessing the same domain. Route53 will identify the resource that provides the fastest response with lowest latency.
• Failover Routing Policy
• Geolocation Routing Policy

42 . How do you monitor Amazon VPC?

You can monitor VPC by using:

• CloudWatch and CloudWatch logs
• VPC Flow Logs

43 . How many Subnets can you have per VPC?

We can have up to 200 Subnets per Amazon Virtual Private Cloud (VPC).

44 . How does Amazon Route 53 provide high availability and low latency?

Here’s how Amazon Route 53 provides the resources in question:

Globally Distributed Servers

Amazon is a global service and consequently has DNS services globally. Any customer creating a query from any part of the world gets to reach a DNS server local to them that provides low latency. 

Dependency

Route 53 provides a high level of dependability required by critical applications

Optimal Locations

Route 53 uses a global anycast network to answer queries from the optimal position automatically.

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

Domain

A domain is a collection of data describing a self-contained administrative and technical unit. For example, www.simplilearn.com is a domain and a general DNS concept.

Hosted zone

A hosted zone is a container that holds information about how you want to route traffic on the internet for a specific domain. For example, lms.simplilearn.com is a hosted zone.

46 . Latency Based Routing and Geo DNS?

The Geo Based DNS routing takes decisions based on the geographic location of the request. Whereas, the Latency Based Routing utilizes latency measurements between networks and AWS data centers. Latency Based Routing is used when you want to give your customers the lowest latency possible. On the other hand, Geo Based routing is used when you want to direct the customer to different websites based on the country or region they are browsing from.

47 . What Is Cloudtrail and How Do Cloudtrail and Route 53 Work Together?

CloudTrail is a service that captures information about every request sent to the Amazon Route 53 API by an AWS account, including requests that are sent by IAM users. It saves log files of these requests to an Amazon S3 bucket. CloudTrail captures information about all requests. You can use information in the CloudTrail log files to determine which requests were sent to Amazon Route 53, the IP address that the request was sent from, who sent the request, when it was sent, and more.

48 . How does AWS IAM help your business?

IAM enables to:

• Manage IAM users and their access – AWS IAM provides secure resource access to multiple users
• Manage access for federated users – AWS allows you to provide secure access to resources in your AWS account to your employees and applications without creating IAM roles

• interviewpitch@gmail.com