AWS Meetup Reflections: Understanding the New Regional RIs

AWS Meetup Reflections: Understanding the New Regional RIs

Anna Kate Tobin
Senior Channel Marketing Manager
May 18, 2017
3 minute read

The content in this blog is outdated and we cannot reliably say it is still accurate with the speed in which the cloud industry moves. But don’t worry—below are more recent, up-to-date blogs.

AWS Rightsizing For Cost Optimization

The 5 Best Ways To Reduce AWS Instance Cost

The Ultimate Guide To Amazon EC2 Reserved Instances


If you haven’t already had the opportunity to check out a Boston AWS Meetup (or the AWS Meetup group local to you), you’re missing out! These are an awesome opportunity to learn about the latest AWS news and features, network with your peers, and wine and dine on free food and drinks.

Our friends at G2 Tech Group were the hosts last week and pulled together an awesome selection of presentations focused on everyone’s favorite theme: saving money! It’s no surprise there was a nice turnout from the local AWS community. It was great to be part of the lineup and present on what’s a very hot topic right now: the new AWS Regional Reserved Instances (RIs). If you’re not familiar with RIs, you can think of them as a coupon. You receive a discount based on a commitment to pay for a certain amount of EC2 instance usage, whether you use the hours or not. Commitment options vary — including all upfront, partial upfront or no upfront payment with 1-3 year terms — as do the discount ranges.

Just when you thought you had RIs figured out, Amazon releases a new type! In this session, we broke down some of the common questions we’ve been hearing from leading cloud consumers.

  • What do I need to know about the new RIs?

  • Why should I care about them?

  • How can I leverage them today?

Luckily, G2 livestreamed the meetup on their Facebook page. Anyone who missed it can check out the replay and presentation deck below.

Here are some key takaways from the session:

What do I need to know and why should I care about the new RIs?

Over the past six months, AWS has revamped its RI offerings for customers. RIs can now be purchased within the scope of an AWS Region as an alternative to the scope of an Availability Zone. This means you no longer need to worry what Availability Zone an RI is running in, so long as it’s within the specified AWS Region. For example, an m4.large coupon purchased in the us-east-1 region could be used within Availability Zones 1a, 1b, 1c within that region.

AWS has also made it easier for customers to ensure their RI coupons cover as many running EC2 instances as possible by floating unused RI hours to other instance types within the same region or family. This automatically maximizes RI savings without the need for manual modifications. For example, the benefit of an unused m4.small coupon would float to an m4.medium instance within the same region, covering one half of its running hours. Shown below, AWS has established normalization factors for converting the benefits of floating RI hours from one instance type to another.

Normalization Factors.png

RIs with a regional scope can be size flexible (Linux/UNIX, shared tenancy) or non-size flexible (all other Regional RIs). The chart below provides an overview of the differences between all available RI options. As you can see, RIs with an Availability Zone scope have the benefit of guaranteed capacity (for the purchasing account), whereas a Regional scope offers more flexible benefits and requires less manual modification.


How can I leverage the new RIs today?

Purchase Reserved Instances! Since Amazon lets you modify your RIs at will, you can change the scope of your instances at any given time, at no additional charge. Simply open the Modify Reserved Instances menu within the AWS console to toggle between the Availability Zone and Region scope options.


You’ll also want to enable the Cost and Usage Report in AWS to allow tracking of where Regional RI credits are being applied. This allows for keeping better tabs on the benefits, and the ability to more easily identify underutilized RIs.

When dealing with large scale environments (i.e. purchasing for many accounts with a large amount of EC2), the best practice is to leverage a third party RI management solution. A solution such as CloudHealth can ensure RI purchasing accuracy, usage and cost savings reporting, and actionable intelligence on when to buy or sell RIs to get the best value.