If you use AWS RIs, you need to use the new queuing option

The AWS reserved instance (AWS RI) offerings got a recent upgrade with the release of a “queue” function. This means that you can now purchase reserved instances that, rather than going into effect immediately, are scheduled for future purchase. (Yes — despite the fact that RI’s have been available for a decade, this is a new feature!)

Back up — what was released?

There are a few variations within the AWS RI purchasing options, such as the term; how much you pay upfront vs. monthly; the option for them to be scheduled; whether the scope of the discount covers instances in a single region or in a particular availability zone; etc.

More on those options and whether you should actually be using Reserved Instances, in this post. (TL;DR: RIs are the right choice when you have 24×7 long-term production workloads; otherwise they’re usually not.)

So, the new feature is the option to purchase these reservation discounts to begin on a future date rather than immediately. This is designed to make it easier for users to have uninterrupted reserved instance coverage. Previously, at the end of a 1- or 3-year term, many users would be unaware that their reservation expired and would have a spike in cost…which they may or may not notice.

How does queuing work?

Before queueing was available, customers had the option to either just go ahead and purchase a new reservation a few days/hours/weeks before the previous RI was due to expire, or set a reminder to go in and buy a new reservation after the previous one had lapsed. Either way, there was an extra cost — either a time window with too many RIs, or one with too few. So it is easy to see that RI queueing can save you money. Queueing can also save you some hassle, as you no longer have to set reminders and build your daily/weekly schedule around going in to buy a new RI. (Reminiscent of some late-night eBay sessions, waiting for the end of an auction to roll around.)

There are a few limitations. AWS RI purchases can be queued for regional Reserved Instances, but not zonal Reserved Instances. Regional RIs are the broader option as they cover any availability zone in a region, while zonal RIs are for a specific availability zone and actually reserve capacity as well.

Cancellation is an option: since payment is processed only at the scheduled purchase time in the queue, you can cancel a purchase at any time before it is processed.

We find it interesting that these are designed as new purchases rather than a “renewable” RIs — likely due to an idea that users may queue an evolving RI type or purchase profile, instead of the same instance type/duration/payment terms over time.

Beware the AWS RI Black Hole

It’s already difficult to shine light on your existing reservations, especially with options in place such as instance size flexibility and the broad applicability of regional RIs.

That’s why ParkMyCloud has released our first support for Reserved Instances this week. You told us that RIs are the next biggest thing that need optimization help on your cloud bills, and we listened. Now, you can see all your AWS RIs — past, present, and queued future purchases — in one place in ParkMyCloud. Next, we’ll be working on more recommendations and optimization — stay tuned!

Originally published at www.parkmycloud.com on October 23, 2019.

CEO of ParkMyCloud