Amazon Elastic Compute Cloud (EC2) is a primary web service provided by AWS and it provides re-sizable compute capacity in the cloud. Compute refers to the computational power required to fulfill your work. Amazon EC2 allows you to acquired compute power through launching of virtual servers called as instances. When you launch an instance, you make use of the compute power as you need. AWS charges you based on the compute power that you have chosen. There are two considerations that you make while launching instances on AWS

  1. The amount of virtual hardware dedicated to the instance
  2. The software loaded on the instance

Amazon Elastic Compute Cloud (EC2) Instance types

There are many instances on AWS based on varying dimentsons of

  1. Virtual CPUs
  2. Memory
  3. Storage
  4. Network Performance

Instance Families

Instances are grouped into Families based on the ratio of the values of the dimensions mentioned above. Within each family, there are several choices that scale up linearly in size. Once you choose a instance family you cannot change it until you do some significant migration exercise.

Example of a instance family in AWS is shown below

For more information on instance types of AWS, click on the link.

Instance Pricing Options

On Demand EC2 Instances

AWS allows a very flexible pricing option and this does not require any upfront commitment. The customer has full control over when the instance is launched and when it is terminated.

Reserved Instances

This option enables the customer to make capacity reservations for predictable workloads. By using reserved instances for these workloads, the customer can save a lot of money as compared to the On-Demand instances. There are two factors which determine the cost of reservation

  1. The term of commitment – Longer the commitment, the bigger the discount.
  2. Payment Option – All upfront, Partial upfront, no upfront. All upfront gives maximum discount

Spot Instances

This option is for workloads that are not time critical. Spot instances offer the greatest discount. With spot instances, the customers specify what price they are ready to pay. When customer’s bid price is more than the current Spot price, the customer will receive the requested instance.

Amazon Elastic Cloud (EC2) Enhanced Networking

For workloads requiring greater network performance, many instance types support Enhanced Networking. Enhanced networking reduces the impact of virtualization on network performance by enabling a capabilities which result in

  1. Improved packets per second (PPS)
  2. Lower Latency
  3. Less Jitter

Instance Store

The instance storage is a temporary storage. The data in the instance store is lost when

  • Underlying disk fails
  • The instance stops
  • The instance terminates

You need to use the S3 or Elastic Block Store (EBS) for persistent data.