Technology - Compute Services Flashcards
EC2
Elastic Compute Cloud. Allows to rent and manage virtual servers in the cloud, providing elastic compute power (scalable). E.g. deploying a database or a web application.
EC2 Instance
A virtual server running on a physical server in a data centre, provading scalable computing capacity in the cloud.
(Instances are not considered serverless.)
EC2 Access Methods
AWS Management Console (web browser)
Secure Shell (SSH; local machine)
EC2 Instance Connect (EIC; IAM policies control SSH access)
AWS System Manager (web browser or AWS CLI)
AMI
Amazon Machine Image. A template that contains the software configuration (ops system, app server and apps) required to launch an instance. E.g.: Amazon Linux, Ubuntu, Windows, Red Hat.
EC2 Features
- Elastic Load Balancing - automatically distributes incoming application traffic across multiple EC2 instances.
- EC2 Auto Scaling - adds or replaces EC2 instances automatically across AZs based on demand.
Horizontal Scaling vs Vertical Scaling
Horizontal Scaling (scaling out) - adding more EC2 instances; reduces the impact of system failures and improves the availability of applications.
Vertical Scaling (scaling up) - upgrade the existing EC2 instance by adding more compute power.
EC2 Pricing: On-Demand
A fixed price in which you are billed to the second based on instance type (pay-as-you-go).
- low cost without upfront payment
- unpredictable workloads that can’t be interrupted
- apps under development
- workloads run no longer than a year
EC2 Pricing: Spot
Take advantage of unused EC2 capacity. Request is fulfilled only if capacity is available.
- not concerned about start/stop
- workloads can be interrupted
- apps feasible at very low compute price
EC2 Pricing: Reserved Instances (RIs)
Commit to a specific instance type in a Region for 1or 3 years.
- steady state usage
- pay money upfront for highest discount
- apps require capacity reservation
EC2 Pricing: Dedicated Hosts
Pay for physical server that is fully dedicated to running your instances.
- bring your own server-bound software license
- regulatory or corporate compliance
EC2 Pricing: Savings Plans
Commit to compute usage, not a dedicated host, with no capacity reservation. Measured per hour, for 1 or 3 years.
- lower bill across multiple compute services
- flexibility to change compute services, instant types, ops systems or regions
Lambda
A serverless, event-driven compute service that lets you run code for virtually any type of application or backend service without provisioning or managing servers.
Use cases include: real-time file processing, sending email notifications, backend business logic
Lambda Features
- Supports popular programming languages.
- You can author code using dev environment or the console.
- Event-driven.
- 15 minutes timeout.
Lambda Pricing
- Compute time: pay only when the code is running.
- Request count: pay for a number of times the function is executed.
- Always free: 1 million free requests each month.
Fargate
A serverless, pay-as-you-go compute engine for containers (Docker) that scales automatically and lets you focus on building applications without managing servers.
