AWS- EC2 Instances Purchasing Options

 OnDemand Instances (EC2--->instances) Pay per second for the running instances. The lifecycle of these instances can be controlled by yo...

 OnDemand Instances (EC2--->instances)

1. Pay per second for the running instances.
2. The lifecycle of these instances can be controlled by you.
3. You can decide when to Start/Stop/Terminate/Hibernate/Reboot.
4. No long-term commitment is required.
5. The price per second is fixed.

Use Case

For short term application

For an irregular workload that cannot be interrupted.

Reserved Instances

Amazon EC2 Reserved Instances (RI) provide a significant discount (up to 72%) compared to On-Demand pricing and provide a capacity reservation when used in a specific Availability Zone.

1. If purchasing option for the EC2 instance is 1 year to 3 years then the Reserved Instance type is the best option.
2. 3 Payment options are available for RI - upfront, Partial upfront, No Upfront 
3. Reserved Instances are charged even there is no use.
4. Purchased RI is non-refundable.

Use Case

For Long Term application

Discounted option as compared to On-Demand Instances.

Spot Instances

Spot Instance AWS Documentation

1. Because Spot Instances enable you to request unused EC2 instances at steep discounts, you can lower your Amazon EC2 costs significantly
2. The hourly price for a Spot Instance is called a Spot price. 
3. Price is less than On-Demand Instances
4. These are selected on the basis of a bid that satisfies the requirement of EC2 instances.

Use Cases

Data Analytics

Batch jobs 

Background processes

How long do AWS spot instances last?

Regular spot pricing—instances can be terminated with 2 minutes notice. Defined duration—you can get a spot instance guaranteed to run for a period of 1-6 hours.