Compute Services Flashcards
What is EC2 (Elastic Compute Cloud)?
Not serverless because there is a server that you directly manage.
A web service that provides secure, resizable compute capacity in the cloud.
It is designed to make web-scale computing easier for developers.
Real world usage: Deploying a database or web application
Describe the On-Demand pricing option for EC2 (Elastic Compute Cloud)
You pay for compute capacity by the hour or the second depending on which instances you run.
No longer-term commitments or upfront payments are needed.
You can increase or decrease your compute capacity depending on the demands of your application and only pay the specified per hourly rates for the instance you use.
What is On-Demand pricing option for EC2 (Elastic Compute Cloud) recommended for?
Users that prefer low cost and flexibility without any up-front payment or long-term commitment.
Applications with short-term, spiky, or unpredictable workloads that cannot be interrupted
Applications being developed or tested on EC2 for the first time.
Describe the Spot pricing option for EC2 (Elastic Compute Cloud)
Available at up to a 90% discount compared to On-Demand prices and let you take advantage of unused Amazon EC2 capacity in the AWS Cloud.
You can significantly reduce the cost of running your applications, grow your application’s compute capacity and throughput for the same budget, and enable new types of cloud computing applications.
What is Spot pricing option for EC2 (Elastic Compute Cloud) recommended for?
Applications that have flexible start and end times
Applications that are only feasible at very low compute prices
Users with urgent computing needs for large amounts of additional capacity
Describe the Reserved Instances pricing option for EC2 (Elastic Compute Cloud)
Significant discount (up to 72%) compared to On-Demand Instance pricing.
You have the flexibility to change families, operating system types, and tenancies while benefitting from Reserved Instance pricing when you use Convertible Reserved Instances.
Describe the Dedicated Host pricing option for EC2 (Elastic Compute Cloud)
A flexible pricing model that offer low prices on EC2 and Fargate usage, in exchange for a commitment to a consistent amount of usage (measured in $/hour) for a one or three year term.
Allow you to use your existing per-socket, per-core, per-VM software licenses to help maintain license compliance.
This is similar to Dedicated Instances, but Dedicated Hosts provide more restrictive control over the server.
Describe the Dedicated Instances pricing option for EC2 (Elastic Compute Cloud)
Ensure your instance will run on a dedicated physical server due to licensing restriction that don’t allow for software to run on a shared tenancy model.
Describe the Savings Plans pricing option for EC2 (Elastic Compute Cloud)
A flexible pricing model that offer low prices on EC2 and Fargate usage, in exchange for a commitment to a consistent amount of usage (measured in $/hour) for a one or three year term.
How can you connect to an EC2 instance from a local machine?
Using secure shell (SSH) allows you to access an EC2 instance from your local laptop using a key pair, which consist of a private key and a public key.
A key pair is needed
Describe the Horizontal scaling feature for EC2 instances.
Scaling out adds or replaces instances
Describe the Vertical scaling feature for EC2 instances.
Scaling up upgrades an existing instance
Describe the Auto scaling feature for EC2 instances.
Helps you maintain application availability and allows you to automatically add or remove EC2 instances according to conditions you define.
You can use the fleet management features of Amazon EC2 Auto Scaling to maintain the health and availability of your fleet.
You can also use the dynamic and predictive scaling features of Amazon EC2 Auto Scaling to add or remove EC2 instances.
Dynamic scaling responds to changing demand and predictive scaling automatically schedules the right number of EC2 instances based on predicted demand.
Dynamic scaling and predictive scaling can be used together to scale faster.
o don’t confuse it with load balancing
How many compute hours do you receive on the Free Tier plan for EC2 instances?
750 compute hours
What are Elastic Load Balancers (ELB)?
Automatically distributes your incoming application traffic across multiple EC2 instances.
Classic
Application
Gateway
Network
Describe a Classic Elastic Load Balancer (ELB).
NOW Amazon Virtual Private Cloud (Amazon VPC)
Retired August 2022 and recommended to migrate to an Amazon Virtual Private Cloud (Amazon VPC).
VPC lets you provision a logically isolated section of the AWS Cloud where you can launch AWS resources in a virtual network that you define.
You have complete control over your virtual networking environment, including selection of your own IP address range, creation of subnets, and configuration of route tables and network gateways.
You can use both IPv4 and IPv6 in your VPC for secure and easy access to resources and applications.
You can easily customize the network configuration for your VPC. For example, you can create a public facing subnet for your web servers that has access to the Internet, and place your backend systems, such as databases or application servers, in a private-facing subnet with no Internet access.
You can leverage multiple layers of security (including security groups and network access control lists) to help control access to EC2 instances in each subnet.
You can create a hardware virtual private network (VPN) connection between your corporate data center and your VPC and leverage the AWS Cloud as an extension of your corporate data center.
Describe an Application Elastic Load Balancer (ELB).
Is best suited for load balancing of HTTP and HTTPS traffic and provides advanced request routing targeted at the delivery of modern application architectures, including microservices and containers.
Operating at the individual request level (Layer seven), Application Load Balancer routes traffic to targets within Amazon Virtual Private Cloud (Amazon VPC) based on the content of the request.