Introduction to AWS

Question 1

What is IaaS

Answer 1

Infrastructure as a service (IaaS)
Basic building blocks for cloud IT: 
• Networking features
• Computers
• Data storage space

Question 2

What is PaaS

Answer 2

Platform as a service (PaaS) enables you to run applications without the need to manage underlying infrastructure (for example, hardware and operating systems).

Question 3

What is SaaS

Answer 3

Software as a service (SaaS) provides you with a completed product that the service provider runs and manages.

Question 4

6 benefits of Cloud Computing

Answer 4

• Trade capital expense for variable expense
• Benefit from massive economies of scale
• Stop guessing capacity
• Increase speed and agility
• Stop spending money on running and maintaining data centers
• Go global in minutes

Question 5

Unmanaged vs. Managed services

Answer 5

Unmanaged services require the user to manage how the service responds to changes in load, errors, and situations where resources become unavailable.

In managed services, scaling, fault tolerance, and availability are tipically built in to the service.

Question 6

Some database services

Answer 6

• Amazon Relational Database Service (Amazon RDS) to work with relational databases
• Amazon ElastiCache to cache frequently accessed data
• Amazon DynamoDB to function as a NoSQL database
• Amazon Redshift for data warehouse capabilities

Question 7

Some analytics services

Answer 7

Amazon Kinesis, Amazon EMR (previously Elastic MapReduce)

Question 8

Some development tools

Answer 8

CodeCommit, CodeDeploy, CodePipeline, Cloud9, Elastic Beanstalk, CloudFormation

Question 9

All-in-cloud / Hybrid

Answer 9

A cloud-based application is fully deployed in the cloud and all parts of the application run in the cloud.

The hybrid deployment is used to extend and grow an organization’s infrastructure into the cloud while connecting cloud resources to the internal system.

Question 10

Some mobile services

Answer 10

• Amazon Simple Notification Service (Amazon SNS) for notifications
• Amazon Cognito for authentication and saving mobile user data
• Amazon Pinpoint to measure and analyze mobile application usage data

Question 11

Principles of microservices

Answer 11

• Each application component runs as its own service
• Each component communicates with other services through a well-defined API.
• Microservices are built around business capabilities.
• Each service performs a single function.

Question 12

Abilities of microservices

Answer 12

• Write microservices using different frameworks and programming languages.
• Deploy them independently, as a single service, or as a group of services.
• Choose the best technology for your workload.

Question 13

Benefits of microservices

Answer 13

• Agility
• Flexible scaling
• Easy deployment
• Technological freedom
• Reusable code
• Resilience

Question 14

Best practices with microservices

Answer 14

• Change components without breaking them
• Use a simple API
• Treat server as stateless

Question 15

What are Regions and Availability zones

Answer 15

AWS Regions are geographic locations that contain multiple Availability Zones.

Each Availability Zone is isolated from failures in other Availability Zones. Each Availability Zone is designed as an independent failure zone.

Each Availability Zone comprises one or more data centers, no data center can be part of two Availability Zones.

Question 16

How to select a region

Answer 16

• Data governance, legal requirements
• Proximity to customers (latency)
• Services available within the region
• Costs

Question 17

What are AMIs

Answer 17

An AMI is an encrypted machine image stored in Amazon Elastic Block Store (ENS) or Amazon Simple Storage Service (S3).
AMIs function similar to a template of a computer’s root drive.
They contain the operating system and can also include software and layers of your application, such as database servers, middleware, and web servers.

Question 18

How do Spot instances work

Answer 18

With Spot Instances, you specify the max price you are willing to pay per instance-hour.

Although the Spot price is below or equal to your max price, you pay the Spot price. If your instance is reclaimed because of an increase in the Spot price above your max price, you will not be charged for the partial hour that your instance has run.

You pay the Spot price that’s in effect for the time period your instances are running. Amazon EC2 sets the Spot Instance price and adjusts it gradually based on long-term trends in supply and demand for Spot Instance capacity.

Question 19

How does Elastic Load Balancing work

Answer 19

Handles the varying load of your application traffic in a single Availability Zone or across multiple Availability Zones.

ELB detects unhealthy instances within a pool and automatically reroutes traffic to healthy instances until the unhealthy instances have been restored.

Question 20

Alternatives to Sticky sessions

Answer 20

• Sessions stored on distributed cache

- Sessions stored on noSQL database, like DynamoDB

Question 21

What does Auto scaling allow

Answer 21

It provides user interface for building scaling plans for resources, including

• Amazon EC2 instances and Spot Fleets
• Amazon Elastic Container Service (Amazon ECS) tasks
• Amazon DynamoDB tables and indexes
• Amazon Aurora replicas.

If Auto Scaling adds more instances => scaling out.
As Auto Scaling terminates instances => scaling in.