Google Cloud recently released a new pricing option: Google Cloud capacity reservations. This new option intended for users with anticipated spikes in usage, such as over holidays or planned backups. It also expanded its Committed Use discount program to apply to more types of resources.
Manish Dalwadi, product manager for Compute Engine, said in Google’s announcement of these releases, “you shouldn’t need an advanced degree in finance to get the most out of your cloud investment.”
We’ve noted Google Cloud’s positioning as “best in customer-first pricing” in previous articles on Sustained Use Discounts and Resource-Based Pricing. However, the new options – particularly capacity reservations – may not be the best example of this.
How Google Cloud Capacity Reservations Work
Google Cloud capacity reservations are a bit different from options we see at the other major cloud providers. They are not a cost-savings plan like the AWS and Azure’s “reserved instance” programs that allow users to pay upfront for lower prices. Instead, they actually reserve capacity, to ensure it’s available when you need it. Use cases include holiday/Black Friday demand, planned organic growth, and backup/disaster recovery.
VMs you have reserved in advance will be billed at the same rate as on-demand. However, other discounts may apply. As you consume reserved VMs, you’ll also get the benefit of any applicable Sustained and Committed Use discounts.
One potential issue is that once you make a reservation, you will continue to consume and be charged for the resources until the reservation expires or you delete it. By default, any instance that matches the reservation configuration will be allocated against the reservation. On the one hand, this can prevent you from having to pay for reserved capacity above what you are using, but this may actually defeat your purpose of trying to have additional guaranteed capacity available. To guarantee the extra capacity for a specific instance even if it is stopped (or “parked” as we like to say), you will need to explicitly set an option when the instance is created. Note that you will still be paying for the reservation if you do not have any running instances that match the reservation.
Another caveat is that “a VM instance can only use a reservation if its properties exactly match the properties of the reservation.“ In other words, you cannot buy a bunch of small reservations and expect that they can be combined into a big reservation, like you can do with certain types of reserved instances from the other cloud providers. This is consistent with the idea of a capacity reservation, rather than a discount program, and is worth keeping in mind.
This is a new avenue for customers to easily commit themselves to spending on resources they may not actually need, so we encourage you to evaluate carefully before reserving capacity and to keep a close watch on your monthly bill and review the cloud waste checklist.
More Committed Use Discounts
Alongside the capacity reservations, Google also announced an expansion of Committed Use Discounts to include GPUs, Cloud TPU Pods, and local SSDs.
Committed Use Discounts are the Google pricing option most analogous to AWS and Azure Reserved Instances. Essentially, you choose how much to purchase in advance for up to a 55% discount. More here: How to Analyze Google Cloud Committed Use Discounts.
Get the Best Pricing for You
Ultimately, Google Cloud pricing fares well on measures of user-friendliness and options for cost savings, but we question if the reserved capacity changes will do anything to improve the readability of the bill. On the other hand, the expansion of Committed Use discounts does provide more savings-in-hand options for customers.