Identify any AWS EC2 instances that can be upgraded to Reserved Instances (RIs) and follow the Cloud Conformity recommendations for purchasing your RIs in order to receive a significant discount on the hourly charges. RIs represent a pricing model that enables discounted hourly rates for compute capacity in exchange of reserving a certain amount of compute usage upfront. The cost savings when using Reserved Instances over On-Demand Instances are up to 75% depending on the commitment term (1-year or 3-years) and the payment option used (No Upfront, Partial Upfront or All Upfront). For example, for a t2.large EC2 instance provisioned in the US-East region (N. Virginia) you can save roughly $24 per month by upgrading it to a Reserved Instance for a period of 1 year with no upfront costs or save $40 per month (as of November 2016) by reserving it for a period of 3 years with a portion of the cost paid upfront (Partial Upfront payment option).
Reserved Instances represent a good strategy to cut down on EC2 costs but purchasing them without a plan can feel like a risky process. The Cloud Conformity purchasing recommendations outlined in this rule will help you optimize your RIs spending and save money by using only what you need.
Note: In order to verify the current status of purchased reserved capacity and provide accurate recommendations, Cloud Conformity needs access to the AWS payer account (the account designated to pay the bills) or to AWS individual accounts. The following IAM policy allows Cloud Conformity to view all the reserved EC2 instances available in your account(s):
To verify your current Amazon EC2 compute capacity and determine if there are any candidates for upgrading to Reserved Instances (RIs), perform the following:
To upgrade your On-Demand EC2 instances to Reserved Instances you need to purchase them wisely in order to avoid paying for resources that you do not need. To make the RI purchase based on the right pricing model, the right size and platform at the right time, follow the recommendations outlined below:
To upgrade to Reserved Instances just purchase RIs in the same region, using the same attributes as your active On-demand instances and the billing will be automatically changed to reflect the reserved rates. To buy the required RIs, perform the following actions:
To renew your existing Reserved Instances (RIs), you need to repurchase them using the same configuration attributes (region, instance type, OS platform, etc). The EC2 RIs are not renewed automatically so you must repurchase your existing RIs in order to avoid On-Demand rates charges when the current reservations expire. To repurchase them perform the following: