Introduction to AWS Flashcards
What is IaaS
Infrastructure as a service (IaaS) Basic building blocks for cloud IT: • Networking features • Computers • Data storage space
What is PaaS
Platform as a service (PaaS) enables you to run applications without the need to manage underlying infrastructure (for example, hardware and operating systems).
What is SaaS
Software as a service (SaaS) provides you with a completed product that the service provider runs and manages.
6 benefits of Cloud Computing
- 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
Unmanaged vs. Managed services
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.
Some database services
- 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
Some analytics services
Amazon Kinesis, Amazon EMR (previously Elastic MapReduce)
Some development tools
CodeCommit, CodeDeploy, CodePipeline, Cloud9, Elastic Beanstalk, CloudFormation
All-in-cloud / Hybrid
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.
Some mobile services
- 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
Principles of microservices
- 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.
Abilities of microservices
- 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.
Benefits of microservices
- Agility
- Flexible scaling
- Easy deployment
- Technological freedom
- Reusable code
- Resilience
Best practices with microservices
- Change components without breaking them
- Use a simple API
- Treat server as stateless
What are Regions and Availability zones
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.
How to select a region
- Data governance, legal requirements
- Proximity to customers (latency)
- Services available within the region
- Costs
What are AMIs
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.
How do Spot instances work
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.
How does Elastic Load Balancing work
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.
Alternatives to Sticky sessions
- Sessions stored on distributed cache
- Sessions stored on noSQL database, like DynamoDB
What does Auto scaling allow
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.
