--- title: "“Apparently I Stuttered: A Compute Optimizer Clarification”" id: "14646" type: "post" slug: "apparently-i-stuttered-a-compute-optimizer-clarification" published_at: "2024-06-26T19:40:36+00:00" modified_at: "2024-06-26T20:09:21+00:00" url: "https://www.lastweekinaws.com/blog/apparently-i-stuttered-a-compute-optimizer-clarification/" markdown_url: "https://www.lastweekinaws.com/blog/apparently-i-stuttered-a-compute-optimizer-clarification.md" excerpt: "There have been some noises about this week's newsletter issue in which I criticized the release of AWS Compute Optimizer offering RDS recommendations...Let me clarify my position and commentary on this feature announcement." taxonomy_category: - "Uncategorized" --- There have been some noises about this week’s newsletter issue in which I criticized the release of [AWS Compute Optimizer offering RDS recommendations](https://aws.amazon.com/about-aws/whats-new/2024/06/aws-compute-optimizer-amazon-rds-rightsizing-recommendations-mysql-postgresql/) thusly: Let me clarify my position and commentary on this feature announcement. **The feature itself is fine, bordering on great.** “You’re running RDS instances of type X, consider type Y instead” is a solid enhancement. For extra style points, it even supports a whole slew of customizations around the recommendations: RI awareness (which we’ll get into in a sec!), idle detection, storage, the lookback period under analysis, and integration with RDS memory metrics for deeper inspection. This is a solid feature enhancement that I’m sure will brighten the days of many customers and represents what I know to be a lot of hard work and internal negotiation to develop and launch. However! My concern with the feature is that customers are inherently limited in their ability to migrate between RDS instance types due to the inflexibility of RDS Reserved Instances and the RDS org not deciding not to support Savings Plans, or even a similar structure that’s worse in every way–like SageMaker’s own imagining of Savings Plans versus supporting the existing ones. While this feature announcement is RI-aware and will make recommendations that take those into account, if a customer has existing high RI coverage on RDS, they may not see recommendations to downsize their over-provisioned RDS instances. That’s my issue: it’s not about this announcement, it’s about the capability being hamstrung by RDS RIs making this less effective than it could be–which is entirely an RDS issue, not an issue with the feature. If there were more flexibility in RDS RIs (Savings Plans!) then this feature might show substantially more optimization opportunities. What do I mean about RDS RI inflexibility? While the discounts can be high (up to 69% discounting off of on-demand pricing), the RIs are bound to a combination of region, database engine, instance class, and deployment type, roughly equivalent to the inflexibility we had with EC2 Standard RIs–and why Compute Savings Plans were such a massive improvement. One of the best parts about Compute Savings Plans is that it doesn’t matter whether you’re using Lambda, Fargate, EC2, what instance family you’re using, etc–as long as you’re spending at least some committed hourly spend amount, there aren’t artificial economic barriers that constrain your architectural decisions. This isn’t the [first time I’ve made this observation](https://www.lastweekinaws.com/blog/the-great-lie/) , [as](https://x.com/nocksers/status/1583597077044822017) [have](https://x.com/nikovirtala/status/1318615778128809984) [many](https://x.com/philsweeney/status/1285878916717010944) [others](https://x.com/fastchicken/status/1717674710639710507) , including the vast majority of our clients privately, and I continue to give the RDS organization a remarkably low score for Customer Obsession. (as another example: gp3 is 20% less expensive per gigabyte than gp2 on EBS, but the per GB cost remains the same between gp2 and gp3 on RDS.) In summary, if you’re running a lot of RDS on-demand (something I strongly advise folks not to do in almost every circumstance) this feature is the cat’s pajamas. If you have high RI coverage on RDS, this feature instead serves as a tantalizing glimpse of a world that the RDS org has firmly shut the door on, at least for the time being. by Corey Quinn Corey is the Chief Cloud Economist at Duckbill, where he specializes in helping companies improve their AWS bills by making them smaller and less horrifying. He also hosts the "Screaming in the Cloud" and "AWS Morning Brief" podcasts; and curates "Last Week in AWS," a weekly newsletter summarizing the latest in AWS news, blogs, and tools, sprinkled with snark and thoughtful analysis in roughly equal measure. ## More Posts from Corey [Back to the Blog](https://www.lastweekinaws.com/blog/) [https://www.lastweekinaws.com/blog/cloudwatch-omni-infinidash-review/](https://www.lastweekinaws.com/blog/cloudwatch-omni-infinidash-review/) ### [Infinidash: AWS’s New Observability Play Has Great Bones and a Terrible Bedside Manner](https://www.lastweekinaws.com/blog/cloudwatch-omni-infinidash-review/) [By Corey Quinn](https://www.lastweekinaws.com/blog/author/cquinn/) Infinidash: AWS’s New Observability Play Has Great Bones and a Terrible Bedside Manner AWS has just released something fascinating in the form of CloudWatch Omni. I want to be upfront before I dive further: “CloudWatch Omni” is a wretched name that I will not be using, so for the rest of this article and the […] [Read More about Infinidash: AWS’s New Observability Play Has Great Bones and a Terrible Bedside Manner](https://www.lastweekinaws.com/blog/cloudwatch-omni-infinidash-review/) [https://www.lastweekinaws.com/blog/reading-observability-tools-thats-a-robots-job/](https://www.lastweekinaws.com/blog/reading-observability-tools-thats-a-robots-job/) ### [Reading Observability Tools? That’s a Robot’s Job](https://www.lastweekinaws.com/blog/reading-observability-tools-thats-a-robots-job/) [By Corey Quinn](https://www.lastweekinaws.com/blog/author/cquinn/) Last Thursday Honeycomb was kind enough to hand me the closing keynote slot at O11yCon, a conference whose entire premise is that observability matters and the people in the room are the ones who would know. I used that slot to argue that the primary reader of your telemetry is no longer a human, and […] [Read More about Reading Observability Tools? That’s a Robot’s Job](https://www.lastweekinaws.com/blog/reading-observability-tools-thats-a-robots-job/) [https://www.lastweekinaws.com/blog/s3-is-not-a-filesystem-but-now-theres-one-in-front-of-it/](https://www.lastweekinaws.com/blog/s3-is-not-a-filesystem-but-now-theres-one-in-front-of-it/) ### [S3 Is Not a Filesystem (But Now There’s One In Front of It)](https://www.lastweekinaws.com/blog/s3-is-not-a-filesystem-but-now-theres-one-in-front-of-it/) [By Corey Quinn](https://www.lastweekinaws.com/blog/author/cquinn/) I’ve been saying “S3 is not a filesystem” for over a decade. I’ve said it on stages, in newsletters, on podcasts, and directly to the faces of large company employees who were too polite to tell me to shut up before they went back to their FUSE monstrosities. It was one of those reliable truths […] [Read More about S3 Is Not a Filesystem (But Now There’s One In Front of It)](https://www.lastweekinaws.com/blog/s3-is-not-a-filesystem-but-now-theres-one-in-front-of-it/) ## Get the newsletter! Stay up to date on the latest AWS news, opinions, and tools, all lovingly sprinkled with a bit of snark. "*" indicates required fields