AWS Interview Questions
1) Explain what is AWS?
AWS stands for Amazon Web Service; it is a collection of remote computing services also known as cloud computing platform. This new realm of cloud computing is also known as IaaS or Infrastructure as a Service.
2) Mention what are the key components of AWS?
The key components of AWS are
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) Explain 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 is the relation between an instance and AMI?
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 compute 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
Amazon S3 is a REST service, you can send request by using the REST API or the AWS SDK wrapper libraries that wrap the underlying Amazon S3 REST API.
8) Mention what is the difference between Amazon S3 and EC2?
The difference between EC2 and Amazon S3 is that
9) How many buckets can you create in AWS by default?
By default, you can create upto 100 buckets in each of your AWS accounts
10) Explain can you vertically scale an Amazon instance? How?
Yes, you can vertically scale on Amazon instance. For that
T2 instances are designed to provide moderate baseline performance and the capability to burst to higher performance as required by workload.
12) 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.
13) Mention what are the security best practices for Amazon EC2?
For secure Amazon EC2 best practices, follow the following steps
The buffer is used to make the system more robust to manage traffic or load by synchronizing different component. Usually, components receive and process the requests in an unbalanced way, With the help of buffer, the components will be balanced and will work at the same speed to provide faster services.
15) 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
Ephermal Storage
Instance Store
Temporary block level storage
Free storage with an EC2 instance
Data is lost when instance is stopped or terminated.
There is no SLA, access speed is not guaranteed.
Buffers, caches, scratch data, etc..,
Replicated data for load-balanced web servers.
Simple Storage service (S3)
First Aws service introduced in 2006
Internet accessible storage via http / https
Audio, Video, images, backup etc..,
unlimited bucket size.
upto 5 TB object size
Priced on storage used and transfer out
it's not a file system
99.99% SLA
Two types of S3 storage
Standard Storage
99.9999999999% durablility.
First 1TB $0.0300/GB
Reduced Redundance Storage (RRS)
First 1 TB $0.0240 /GB
Reduced durablility - 99.99%
Elastic Block Storage - EBS
Not Internet accessible
Persistent file system for EC2
Does not need to be attached to an instance
can be transferred between AZ
Supports incremental snapshots.
EBS leverages S3 for snapshot storage.
Provisioned IOPS.
Glacier
Very cheap storage
Useful for infrequently used data. Ideal for backup.
Very very slow retrieval times (4 - 6 hours)
High durablility.
Cost for restore
AES 256 bit data encryption.
0.01 cents per GB.
EC2 pricing
on-demand instance
Reserve Instance
Less expensive
Requires a commitment
has an upfront cost
Lower hourly rate
RI can be sold on the AWS Market Place
you commit to utilization
Light utilization RI's
Ideal for couple of hours a day
Medium Utilization RI's
Ideal for could of hours a day or couple of days a week.
Heavy Utilization RI'sold
Commiting to running 100%
Highest Savings
Spot Instances
Unused AWS Capacity
Very Cheap hourly rate.
Not guaranteed
AWS Networking, Cloudwatch and Autoscaling
Logically isolated Network in the Aws cloud
Control of Network architecture
Enhanced Security
Internetwork with other organizations.
Elastic IP Address (Public IP's)
Enable Hybrid cloud
VPC Cost = $0
VPN Cost is $0.05/hr
Elastic Load Balancing
Region wide load balancer
can be used internally or externally
SSL Termination and processing.
ELB EC2 health checks
Route performs ELB health checks
Route 53
DNS is crucial for any environment.
World wide distributed DNS
Route 53 has 100% SLA
Route 53 uptime.
Cloud Watch
Basic Monitoring. It is free upto 7 metrics, for 5 min interval.
Detailed Monitoring
set alarms and alerts
Notfication via SES, SNS
Integrate with Auto Scaling
Mobile APP for basic monitoring and management.
Auto Scaling
Expand or shrink your EC2
Cloudwatch or manual schedule configuration
Notifications
service is free of cost.
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How to Migrate your VM from Vcenter to AWS EC2 using AWS connector
https://docs.aws.amazon.com/amp/latest/userguide/migrate-vms.html
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AWS stands for Amazon Web Service; it is a collection of remote computing services also known as cloud computing platform. This new realm of cloud computing is also known as IaaS or Infrastructure as a Service.
2) Mention what are the key components of AWS?
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 very useful in case of unpredictable workloads
- Elastic Block Store (EBS): It provides persistent storage volumes that attach to EC2 to allow you to persist data past the lifespan of a single EC2
- CloudWatch: To monitor AWS resources, It allows administrators to view and collect key Also, one can set a notification alarm in case of trouble.
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) Explain 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 is the relation between an instance and AMI?
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 compute 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
Amazon S3 is a REST service, you can send request by using the REST API or the AWS SDK wrapper libraries that wrap the underlying Amazon S3 REST API.
8) Mention what is the difference between Amazon S3 and EC2?
The difference between EC2 and Amazon S3 is that
| EC2 | S3 |
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By default, you can create upto 100 buckets in each of your AWS accounts
10) Explain can you vertically scale an Amazon instance? How?
Yes, you can vertically scale on 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
T2 instances are designed to provide moderate baseline performance and the capability to burst to higher performance as required by workload.
12) 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.
13) Mention what are the security best practices for Amazon EC2?
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 your require
- Disable password-based login, for instance, launched from your AMI
The buffer is used to make the system more robust to manage traffic or load by synchronizing different component. Usually, components receive and process the requests in an unbalanced way, With the help of buffer, the components will be balanced and will work at the same speed to provide faster services.
15) 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
- Unprotected private key file
- Server refused our key or No supported authentication method available
- Error using MindTerm on Safari Browser
- Error using Mac OS X RDP Client
Ephermal Storage
Instance Store
Temporary block level storage
Free storage with an EC2 instance
Data is lost when instance is stopped or terminated.
There is no SLA, access speed is not guaranteed.
Buffers, caches, scratch data, etc..,
Replicated data for load-balanced web servers.
Simple Storage service (S3)
First Aws service introduced in 2006
Internet accessible storage via http / https
Audio, Video, images, backup etc..,
unlimited bucket size.
upto 5 TB object size
Priced on storage used and transfer out
it's not a file system
99.99% SLA
Two types of S3 storage
Standard Storage
99.9999999999% durablility.
First 1TB $0.0300/GB
Reduced Redundance Storage (RRS)
First 1 TB $0.0240 /GB
Reduced durablility - 99.99%
Elastic Block Storage - EBS
Not Internet accessible
Persistent file system for EC2
Does not need to be attached to an instance
can be transferred between AZ
Supports incremental snapshots.
EBS leverages S3 for snapshot storage.
Provisioned IOPS.
Glacier
Very cheap storage
Useful for infrequently used data. Ideal for backup.
Very very slow retrieval times (4 - 6 hours)
High durablility.
Cost for restore
AES 256 bit data encryption.
0.01 cents per GB.
EC2 pricing
on-demand instance
Reserve Instance
Less expensive
Requires a commitment
has an upfront cost
Lower hourly rate
RI can be sold on the AWS Market Place
you commit to utilization
Light utilization RI's
Ideal for couple of hours a day
Medium Utilization RI's
Ideal for could of hours a day or couple of days a week.
Heavy Utilization RI'sold
Commiting to running 100%
Highest Savings
Spot Instances
Unused AWS Capacity
Very Cheap hourly rate.
Not guaranteed
AWS Networking, Cloudwatch and Autoscaling
Logically isolated Network in the Aws cloud
Control of Network architecture
Enhanced Security
Internetwork with other organizations.
Elastic IP Address (Public IP's)
Enable Hybrid cloud
VPC Cost = $0
VPN Cost is $0.05/hr
Elastic Load Balancing
Region wide load balancer
can be used internally or externally
SSL Termination and processing.
ELB EC2 health checks
Route performs ELB health checks
Route 53
DNS is crucial for any environment.
World wide distributed DNS
Route 53 has 100% SLA
Route 53 uptime.
Cloud Watch
Basic Monitoring. It is free upto 7 metrics, for 5 min interval.
Detailed Monitoring
set alarms and alerts
Notfication via SES, SNS
Integrate with Auto Scaling
Mobile APP for basic monitoring and management.
Auto Scaling
Expand or shrink your EC2
Cloudwatch or manual schedule configuration
Notifications
service is free of cost.
###############################################################################
How to Migrate your VM from Vcenter to AWS EC2 using AWS connector
https://docs.aws.amazon.com/amp/latest/userguide/migrate-vms.html
###########################################################################
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