4.1 EC2 Introduction I

Amazon Elastic Compute Cloud (EC2) is a web service that provides resizable compute capacity in the cloud. EC2 reduces the time required to obtain and boot new server instance to minutes, allowing you to quickly scale capacity, both up and down, as your computing requirements change. EC2 instance is just like virtual machine, and it allows you to pay only for capacity that you actually use. EC2 provides developers the tools to build failure resilient applications and isolate themselves from common failure scenarios.

EC2 Options

• On demand - allow you to pay a fixed rate by the second (it used to by both of the hour and second) with no commitment.

• Reserved - provide you with a capacity reservation, and offer a significant discount on the hourly charge for an instance. 1 year or 3 year terms. Pay upfront, get discount.

• Spot - enable you to bid whatever price you want for instance capacity, providing for even greater savings if your applications have flexible start and end times.

• Dedicated Hosts - Physical EC2 server dedicated for your use. Dedicated Hosts can help you reduce costs by allowing you to use your existing server-bound software licenses.

On Demand

Users that want the low cost and flexibility of EC2 without any upfront 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.

Reserved

Applications with steady state or predictable usage.

Applications that require reserved capacity.

Users able to make upfront payments to reduce their total computing costs even further:

• Standard RI (Reserved Instances)

• Convertible RI

• Scheduled RI

Spot

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.

Dedicated Hosts

Useful for regulatory requirements that may not support multitenant virtualization.

Great for licensing which doesn't support multi-tenancy or cloud deployments.

Can be purchased On-Demand (hourly).

Can be purchased as a Reservation for up to 70% off the On-Demand price.

EC2 Instance Types

Letter - stands for the speciality.

Number - stands for the generation of this speciality of Instance.

How to remember them? DR Mc GIFT PX (Mc医生的礼品画片).

• D - Density

• I - IOPS (Input/output operations per second)

• R - RAM

• T - cheap general purpose

• M - main choice for general purpose apps

• C - Compute

• G - Graphics

• F - FPGA

• P - GPU

• X - extreme memory

Exam Tips EC2

Know the differences between different pricing models:

• On demand

• Spot

• Reserved

• Dedicated Hosts

Remember with Spot Instances:

• If you terminate the instance, you pay for the hour

• If AWS terminates the spot instance, you get the hour it was terminated in for free.

• Similar to On-Demand instances, partial hours of Spot Instance are billed as full hours, except it is terminated by AWS. In this case the customer will not be charged for the partial hour.

• With Spot instances, you will never be charged more than the maximum price you specified.