EC2, Instance Purchasing Options and EC2 Storage Flashcards
Is EC2 IaaS, PaaS and SaaS?
Infrastructure as a service
It mainly consists in the capability of :
* Renting virtual machines (EC2)
* Storing data on virtual drives (EBS)
* Distributing load across machines (ELB)
* Scaling the services using an auto-scaling group (ASG)
What is EC2 User Data
EC2 user data is a script that runs once at instance first start, it is used to automate boot tasks such as:
* installing updates
* installing softwares and dependencies
* downloading files from the internet
What are Security groups and what role do they play in EC2 instances ?
Security groups is like a virtual bouncer at the door of your EC2 instance with specific rules
* They control who gets in and out of your EC2 instance!
* One security group can guard several EC2 instances, meaning multiple instances can share the same rules.
* Security groups live outside the EC2 instance. If the bouncer blocks someone, the instance inside doesn’t even know they tried to visit.
* It’s locked to a specific region and VPC, so the bouncer only works in its assigned neighborhood.
* The bouncer stops all inbound traffic by default but lets everything outbound through.
What type of EC2 instance is best for short workloads with predictable pricing and charges by the second?
On-Demand Instances – Best for short workloads, predictable pricing, and pay by the second.
What type of EC2 instance is ideal for long workloads and steady-state applications, offering discounts of up to 72%?
Reserved Instances – For long workloads, steady-state applications with up to 72% discount.
Which purchasing option allows long workloads with flexible instance types?
Convertible Reserved Instances – Long workloads with flexible instance choices.
Which EC2 option offers discounts based on commitment to a certain amount of usage for 1 or 3 years?
Savings Plans – Long workloads with commitment to usage, offering discounts for 1 or 3 years.
What instance type offers discounts of up to 90% but can be terminated when the current spot price exceeds your max price?
Spot Instances – Short workloads with up to 90% discount, less reliable since instances can be lost.
Which EC2 option allows you to book an entire physical server for your use, offering control over instance placement? - also most expensive
Dedicated Hosts – The most expensive option but allows control over instance placement.
What purchasing option ensures no other customers will share your hardware?
Dedicated Instances – Instances that run on hardware dedicated to you, with no other customers sharing the hardware.
Which instance type is most cost-efficient in AWS?
Spot Instances – The most cost-efficient instance type with up to 90% discount compared to on-demand.
Which instance option allows you to address compliance requirements and use existing software licenses?
Dedicated Hosts – Allows compliance requirements and use of server-bound software licenses.
What happens if you stop a Capacity Reservation
You can reserve capacity and create or cancel at any time.
What happens if you don’t use the reserved capacity in Dedicated Hosts or Instances?
Dedicated Hosts & Instances – You are charged on-demand rate whether you run instances or not.
Can Reserved Instances be sold or bought in the marketplace?
Yes – Reserved Instances can be sold or bought in the Reserved Instance Marketplace.
