AWS Interview Questions and Answers

1) Explain what AWS is?

AWS stands for Amazon Web Service; it is a collection of remote computing services also known as a cloud computing platform. This new realm of cloud computing is also known as IaaS or Infrastructure as a Service.


2) 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.


3) Explain what S3 is?

S3 stands for Simple Storage Service. You can use S3 interface to store and retrieve any amount of data, at any time and from anywhere on the web. For S3, the payment model is “pay as you go.”


4) What is AMI?

AMI stands for Amazon Machine Image. It’s a template that provides the information (an operating system, an application server, and applications) required to launch an instance, which is a copy of the AMI running as a virtual server in the cloud. You can launch instances from as many different AMIs as you need.


5) Mention what the relationship between an instance and AMI is?

From a single AMI, you can launch multiple types of instances. An instance type defines the hardware of the host computer used for your instance. Each instance type provides different computer and memory capabilities. Once you launch an instance, it looks like a traditional host, and we can interact with it as we would with any computer.


6) What does an AMI include?

An AMI includes the following things

A template for the root volume for the instance

Launch permissions decide which AWS accounts can avail the AMI to launch instances

A block device mapping that determines the volumes to attach to the instance when it is launched


7) How can you send a request to Amazon S3?

Amazon S3 is a REST service, and you can send a request by using the REST API or the AWS SDK wrapper libraries that wrap the underlying Amazon S3 REST API.


8) How many buckets can you create in AWS by default?

By default, you can create up to 100 buckets in each of your AWS accounts.


9) Explain can vertically scale an Amazon instance? How?

Yes, you can vertically scale on the Amazon instance. For that

Spin up a new larger instance than the one you are currently running

Pause that instance and detach the root webs volume from the server and discard

Then stop your live instance and detach its root volume

Note the unique device ID and attach that root volume to your new server

And start it again


10) Explain what T2 instances is?

T2 instances are designed to provide moderate baseline performance and the capability to burst to higher performance as required by the workload.


11) In VPC with private and public subnets, database servers should ideally be launched into which subnet?

With private and public subnets in VPC, database servers should ideally launch into private subnets.


12) Mention what the security best practices for Amazon EC2 are?

For secure Amazon EC2 best practices, follow the following steps

Use AWS identity and access management to control access to your AWS resources

Restrict access by allowing only trusted hosts or networks to access ports on your instance

Review the rules in your security groups regularly

Only open up permissions that you require

Disable password-based login, for example, launched from your AMI


13) Explain how the buffer is used in Amazon web services?

The buffer is used to make the system more robust to manage traffic or load by synchronizing different components. Usually, components receive and process the requests in an unbalanced way. With the help of a buffer, the components will be balanced and will work at the same speed to provide faster services.


14) While connecting to your instance what are the possible connection issues one might face?

The possible connection errors one might encounter while connecting instances are

Connection timed out

User key not recognized by the server

Host key not found, permission denied

An unprotected private key file

The server refused our key or No supported authentication method available

Error using MindTerm on Safari Browser

Error using Mac OS X RDP Client


15) What are key pairs in AWS?

Key pairs are secure login information for your virtual machines. To connect to the instances, you can use key pairs that contain a public key and private key.


16) Is the property of broadcast or multicast supported by Amazon VPC?

No, currently Amazon VPI does not provide support for broadcast or multicast.


17) How many Elastic IPs is allows you to create by AWS?

5 VPC Elastic IP addresses are allowed for each AWS account.


18) Explain default storage class in S3

The default storage class is a Standard frequently accessed.


19) What are the Roles?

Roles are used to providing permissions to entities that you can trust within your AWS account. Roles are very similar to users. However, with roles, you do not require to create any username and password to work with the resources.


20) What are the edge locations?

The edge location is the area where the contents will be cached. So, when a user is trying to accessing any content, the content will automatically be searched in the edge location.