Elastic Compute Cloud(EC2) Flashcards
What does Elastic mean in EC2?
This means that resources can grow or shrink based on the needs/load on the application
What is an EC2 instance?
A web service with which you can run vritua servcer “Instances” in the cloud
What are the methods to access an EC2 instance?
- AWS Management Console
- EC2 Instance Connect(EIC)
- Secure Shell(SSH)
- AWS Systems Manager
What is the AWS Management Console?
Configure and manage instance via a web browser
What is the EC2 Instance Connect(EIC)?
EIC allows for the use of IAM policies to control SSH access to your instances
In what way does EIC impact SSH?
Removes the need to manage SSH
What are the key items to know about SSH?
- Allows you to establish a secure connection to your instance from your local laptop
- This tends to be the most popular
How to configure SSH on the EC2 instance?
Generate a Key Pair and place them on the EC2 Instance
What are the different prcing options for EC2?
- On-Demand
- Spot
- Reserve Instance
- Dedicated Hosts
- Savings Plan
What is the On-Demand Pricing Option?
A fixed price in which you are billed down to the second based on the instance type
When would you use an On-Demand Pricing Option?
- Cost is not your highest concern
- Your application has unpredictable workloads that can’t be interrupted
- Your applications are under development
- Your workloads will not run longer than a year
What is reserve capacity for On-demand?
EC2 capacity is held for you whether or not you run the instance
What is the Spot Option?
- You pay the spot price that’s in effect at the beginning of each hour
- Requests are only fulfilled when capacity is available
When should a spot instance be used?
- You are not concerned about the start or stop time of your application
- Your workloads can be interrupted
- Your application is only feasible at a very low compute price
- Users with an urgent need for a large amount of additioanl compute capacity
What is Reserve Instances Pricing Option?
allow you to commit to a specific instance type in a particular Region for 1 or 3 years
When would you use an Rls?
- Your application has a steady-state usage, and you can commit to 1 or 3 years
- You can pay money upfront in order to receive a discount on On-Demand prices
- Your application requires a capacity reservation
Do you need to sign a contract for a reserved instance ?
You are required to sign a contract
What is a Dedicated Hosts pricing plan?
Allow you to pay for physical server that is fully dedicated to running your instance
When would you use a dedicated host?
- You want to bring your own server bound software license from vendors like Microsoft or Oracle
- You have regulatory or corporate compliance requirements around the tenancy model
What are some fun facts about Dedicated Hosts?
- You can save up to 70% off On-Demand prices
- You bring your existing per-socket, per-core, or per-VM software licenses
- There is no multi-tenancy, meaning their server is not shared with other customers
- A Dedicated Host is a physical server, whereas a Dedicated Instance run on the host
What is a saving pricing plan?
Allows you to commit to compute usage (measured per hour) for 1 to 3 years
When should you use a Savings Plans?
- You want to lower your bull across multiple compute services
- You want the flexibility to change compute service, instance types, operating systems, or regions
What are some fun facts about Savings Plans?
- You can save up to 72% off On-Demand Prices
- You are not making a commitment to a dedicated Host, just compute usage
- Savings can be shared across various computing services like EC2, Fargate, and Lambda
- This does not provide a capacity reservation
What does AMI stand for?
Anmazon Machine Image
What is an AMI ?
Is a special type of virtual applicate that is used to create a vritual machine within the Amazon EC2 Instance
What is included in an AMI instance?
- One or more Amazon Elastic Block Store snapshots, or for instance-store-backed AMIs, a template for the root volume of the instance(For Example, an operating system, an application server and applications)
- Launch Permissions that control which AWS accounts can use the AMI to laucnh instances
- A block device mapping that specifies the volume to attach to the instance when it’s launched
What are the 3 categories that AMI come in?
- Community AMI
- AWS Marketplace AMI
- My AMis
What is an Community AMI?
Free to use, generally you just select the operating you want
What is an AMI Marketplace AMI?
Pay to use, generally come packaged with addtional licensed software
What is “My AMI” ?
AMIs that you have created yourself
What are the 3 ways to pay for a reserve instance ?
- All Upfront
- Partial Upfront
- No Upfront
How much can switching to a RIs pricing option save you over on-demand prices?
You can save up to 75% off On-Demand prices
