What is the Amazon EC2 Cloud

EC2 is the virtual host component of Amazon Web Services (AWS). Amazon Elastic Computer Cloud (EC2) is a web service that allows scalable computer capacity within a "cloud" environment. It enables developers to easily manage configuration and capacity. Each server/application/database server/load balancer etc, that run on EC2 is called an "instance".

Users can pay by the hour or by the amount of capacity and transfer actually used. Amazon advertising describes the pricing scheme as "you pay for resources you consume,"

In contrast, traditional hosting services generally provide a fixed number of resources for a fixed amount of time, therefore if capacity needs to change quickly it is not as cost effective or flexible.

Other features of EC2

Amazon CloudWatch

Allows users to monitor their EC2 instances Also provides metrics such as CPU utilization, disk reads and writes, and network traffic

Auto Scaling

This is particularly good for instances that experience hourly, daily, or weekly variability in usage. Users can set their own variables which will automatically be followed.

Elastic Load Balancing

This distributes incoming application traffic across multiple Amazon EC2 instances providing the right amount of capacity at the desired time. If the load balance is not correct due to faulty instances it will route traffic away from this until they have been fixed

Reserved Instances

Users pay a low, one-time fee and in turn receive a discount on the hourly usage charge for that instance. For applications that require servers to be available at all times this can give substantial savings. If the amount of capacity needed is likely to fluctuate a combination of reserved and on demand instances can also provide significant savings.

Spot Instances

Spot Instances enable users to bid for unused Amazon EC2 capacity. Prices for spot instances vary depending on availability and demand. For users with flexibility on the times they need EC2 services, spot instances can lowers costs.

Amazon Elastic Block Storage (EBS)

EBS provides block level storage volumes for use with Amazon EC2 instances. It allows users to create storage volumes from 1 GB to 1 TB. These EBS are stored apart from the instance and are also independent to the term of the instance. Any amount of EBS can be attached to any instance