AWS Interview Flashcards
What is EC2
EC2, 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
What is SnowBall
SnowBall is a small application that enables you to transfer terabytes of data inside and outside of the AWS environment
What is CloudWatch
CloudWatch helps you to monitor AWS environments like EC2, RDS Instances, and CPU utilization. It also triggers alarms depending on various metrics
What is Elastic Transcoder
Elastic Transcoder is an AWS Service Tool that helps you in changing a video’s format and resolution to support various devices like tablets, smartphones, and laptops of different resolutions.
What do you understand by VPC
VPC stands for Virtual Private Cloud. It allows you to customize your networking configuration. VPC is a network that is logically isolated from other networks in the cloud. It allows you to have your private IP Address range, internet gateways, subnets, and security groups.
DNS and Load Balancer Services come under which type of Cloud Service
DNS and Load Balancer are a part of IaaS-Storage Cloud Service
What are the Storage Classes available in Amazon S3
Storage Classes available with Amazon S3 are:
Amazon S3 Standard Amazon S3 Standard-Infrequent Access Amazon S3 Reduced Redundancy Storage Amazon Glacier
Explain what T2 instances are
T2 Instances are designed to provide moderate baseline performance and the capability to burst to higher performance as required by the workload
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 which contain a Public Key and a Private Key
How many Subnets can you have per VPC
You can have 200 Subnets per VPC
List different types of Cloud Services
Different types of Cloud Services are:
Software as a Service (SaaS) Data as a Service (DaaS) Platform as a Service (PaaS) Infrastructure as a Service (IaaS)
Explain what S3 is
S3 stands for Simple Storage Service. You can use the 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”.
How does Amazon Route 53 provide high availability and low latency
Amazon Route 53 uses the following to provide high availability and low latency:
Globally Distributed Servers - Amazon is a global service and consequently has DNS Servers 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 serves the requests from the nearest data center to the client sending the request. AWS has data-centers across the world. The data can be cached on different data-centers located in different regions of the world depending on the requirements and the configuration chosen. Route 53 enables any server in any data-center which has the required data to respond. This way, it enables the nearest server to serve the client request, thus reducing the time taken to serve
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
What does AMI include
An AMI includes the following things:
A template for the root volume for the instance. Launch permissions to 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
What are the different types of Instances
Following are the types of instances:
Compute Optimized
Memory-Optimized
Storage Optimized
Accelerated Computing
General Purpose
What is the relation between the Availability Zone and Region
An AWS Availability Zone is a physical location where an Amazon data center is located. On the other hand, an AWS Region is a collection or group of Availability Zones or Data Centers.
This setup helps your services to be more available as you can place your VMs in different data centers within an AWS Region. If one of the data centers fails in a Region, the client requests still get served from the other data centers located in the same Region. This arrangement, thus, helps your service to be available even if a Data Center goes down
How do you monitor Amazon VPC
You can monitor Amazon VPC using:
CloudWatch VPC Flow Logs
What are the different types of EC2 instances based on their costs
The three types of EC2 instances based on the costs are:
On-Demand Instance - These instances are prepared as and when needed. Whenever you feel the need for a new EC2 instance, you can go ahead and create an on-demand instance. It is cheap for the short-time but not when taken for the long term.
Spot Instance - These types of instances can be bought through the bidding model. These are comparatively cheaper than On-Demand Instances.
Reserved Instance - On AWS, you can create instances that you can reserve for a year or so. These types of instances are especially useful when you know in advance that you will be needing an instance for the long term. In such cases, you can create a reserved instance and save heavily on costs
What do you understand by stopping and terminating an EC2 Instance
Stopping an EC2 instance means to shut it down as you would normally do on your Personal Computer. This will not delete any volumes attached to the instance and the instance can be started again when needed.
On the other hand, terminating an instance is equivalent to deleting an instance. All the volumes attached to the instance get deleted and it is not possible to restart the instance if needed at a later point in time
What are the consistency models for modern DBs offered by AWS
Eventual Consistency - It means that the data will be consistent eventually, but may not be immediate. This will serve the client requests faster, but chances are that some of the initial read requests may read the stale data. This type of consistency is preferred in systems where data need not be real-time. For example, if you don’t see the recent tweets on Twitter or recent posts on Facebook for a couple of seconds, it is acceptable.
Strong Consistency - It provides an immediate consistency where the data will be consistent across all the DB Servers immediately. Accordingly. This model may take some time to make the data consistent and subsequently start serving the requests again. However, in this model, it is guaranteed that all the responses will always have consistent data
What is Geo-Targeting in CloudFront
Geo-Targeting enables the creation of customized content based on the geographic location of the user. This allows you to serve the content which is more relevant to a user. For example, using Geo-Targeting, you can show the news related to local body elections to a user sitting in India, which you may not want to show to a user sitting in the US. Similarly, the news related to Baseball Tournament can be more relevant to a user sitting in the US, and not so relevant for a user sitting in India
What are the advantages of AWS IAM
AWS IAM enables an administrator to provide granular level access to different users and groups. Different users and user groups may need different levels of access to different resources created. With IAM, you can create roles with specific access-levels and assign the roles to the users.
It also allows you to provide access to the resources to users and applications without creating the IAM Roles, which is known as Federated Access
What do you understand by a Security Group
When you create an instance in AWS, you may or may not want that instance to be accessible from the public network. Moreover, you may want that instance to be accessible from some networks and not from others.
Security Groups are a type of rule-based Virtual Firewall using which you can control access to your instances. You can create rules defining the Port Numbers, Networks, or protocols from which you want to allow access or deny access
