Reserved Instances discount is getting applied automatically, you don't need to modify or change anything (and, there's also no functionality to modify RDS RI). In case with RDS, as mentioned in the previous response, only certain DB platforms are size-flexible, and if you run MySQL, then your MySQL RIs are also size-flexible. It means that regardless of the size of your actual running DB instance, the RI discount will still apply. For example:
- If you have one **db.m5.large** RI, and you run one **db.m5.large** instance (assuming that all the attributes match), then the discount will apply exactly as it is
- If you still keep your **db.m5.large** RI, but you increase the size of your DB instance to **db.m5.xlarge** - then the RI will only cover 50% of your running instance. The remaining 50% (each hour) will be charged on-demand.
If your RI was larger than your running instance, in that case 50% of your RI would not be utilized (lost discount). See more info in the docs: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/apply_ri.html (I know it's documentation for EC2, but in terms of applying RI discount and size flexibility, it works the same). Answer from Nataliya G. on repost.aws
Amazon Web Services
docs.aws.amazon.com › amazon rds › user guide › what is amazon relational database service (amazon rds)? › db instance billing for amazon rds › reserved db instances for amazon rds
Reserved DB instances for Amazon RDS - Amazon Relational Database Service
If the modification is outside the specifications, such as changing the instance class, the discount no longer applies. For more information, see Size-flexible reserved DB instances. ... For more information about reserved DB instances, including pricing, see Amazon RDS reserved instances
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Reserved Instances discount is getting applied automatically, you don't need to modify or change anything (and, there's also no functionality to modify RDS RI). In case with RDS, as mentioned in the previous response, only certain DB platforms are size-flexible, and if you run MySQL, then your MySQL RIs are also size-flexible. It means that regardless of the size of your actual running DB instance, the RI discount will still apply. For example:
- If you have one **db.m5.large** RI, and you run one **db.m5.large** instance (assuming that all the attributes match), then the discount will apply exactly as it is
- If you still keep your **db.m5.large** RI, but you increase the size of your DB instance to **db.m5.xlarge** - then the RI will only cover 50% of your running instance. The remaining 50% (each hour) will be charged on-demand.
If your RI was larger than your running instance, in that case 50% of your RI would not be utilized (lost discount). See more info in the docs: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/apply_ri.html (I know it's documentation for EC2, but in terms of applying RI discount and size flexibility, it works the same).
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Thanks for the reply. We are using mysql 5.7.33 version. I am not able to see any option to modify the reserved instance. Can you guide me on that?
Videos
Amazon Web Services
docs.aws.amazon.com › amazon rds › user guide › managing an amazon rds db instance › modifying an amazon rds db instance
Modifying an Amazon RDS DB instance - Amazon Relational Database Service
To modify a DB instance by using the Amazon RDS API, call the ModifyDBInstance operation. Specify the DB instance identifier, and the parameters for the settings that you want to modify.
Reddit
reddit.com › r/aws › changing class of a reserved instance in rds from m3 to m5?
r/aws on Reddit: Changing class of a reserved instance in RDS from m3 to m5?
January 26, 2022 -
I mistakenly created an RDS reserved instance for a db.m3.medium when i meant to use a db.m5.large and i'm wondering if its too late to change?
related to this oopsie, if i create a reserved instance with multi-az, is it possible to use it for an instance that does not use multi-az?
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i'm wondering if its too late to change? Yes, but also maybe not -- I would talk to your account rep or file a support ticket ASAP. They will likely be willing to fix it for you as a one-off kindness, but there are no guarantees. if i create a reserved instance with multi-az, is it possible to use it for an instance that does not use multi-az? Yup, it's actually quite flexible. Read the section titled "Reserved Instance Size Flexibility" in the RDS RI page .
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if i create a reserved instance with multi-az, is it possible to use it for an instance that does not use multi-az? Yes, but you'd be wasting half the money.. your can use a multi az rds to cover two single az rds of the same instance type and size, or even 4 single az instances at half the size. Ie 1 * m5.xlarge multi az = 4 * m5.large single az
AWS
aws.amazon.com › database › amazon rds › reserved instances
Amazon RDS Reserved Instances | Cloud Relational Database | Amazon Web Services
5 days ago - Use the describe-reserved-db-instances command to list the existing RIs for an account. Please refer to Amazon RDS FAQs for information about using the AWS APIs.
Trend Micro
trendmicro.com › cloudoneconformity › knowledge-base › aws › RDS › unused-reserved-instances.html
Unused RDS Reserved Instances | Trend Micro
November 8, 2022 - 09 Change the AWS region by updating the --region command parameter value and perform the entire audit process for other regions. Because AWS RDS Standard Reserved are reserved for you at purchase, you cannot modify, cancel or sell these reservations and you will be billed for these resources ...
Cloudchipr
cloudchipr.com › blog › aws-reserved-instances
AWS Reserved Instances Explained: Know Exactly How They Work—and Why They Matter
RIs remain relevant for specific scenarios – for example, they can reserve capacity in a particular Availability Zone, and they apply to services like RDS which are not covered by Savings Plans. In this comprehensive guide, we’ll focus primarily on AWS EC2 Reserved Instances (often referred to as reserved instances in AWS or AWS EC2 Reserved Instances) and cover everything from regional vs. zonal scopes, types and classes of RIs, how discounts are applied and billed, to practical aspects like how to purchase, modify, or even sell RIs on the marketplace.
AWS
aws.amazon.com › about-aws › whats-new › 2017 › 10 › amazon-rds-reserved-instances-offer-instance-size-flexibility
Amazon RDS Reserved Instances Offer Instance Size Flexibility - AWS
Since you’re no longer tied to a specific DB instance size or Multi-AZ configuration, you can enjoy the discount even if your database needs change. Amazon RDS Reserved Instance size flexibility is offered in all regions for the MySQL, MariaDB, PostgreSQL, and Amazon Aurora database engines, as well as the “bring your own license” (BYOL) edition of the Oracle database engine.
Reddit
reddit.com › r/aws › upgrading reserved rds instance
r/aws on Reddit: Upgrading reserved RDS instance
May 6, 2017 -
Hi so I wanted my mysql RDS instance upgraded to 5.7.21.
However the issue is I have a reserved instance for 1 year term running mysql 5.5.53.
I tried upgrading the 5.5.53 instance but it will only let me upgrade upto 5.6.x
My question is, can I move the reserved instance remaining days to a new instance with mysql version 5.7.21 ? Kindly assist. Thanks!
Top answer 1 of 4
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I don't believe the reserved instance has got anything to do with your software version. There must be some other reason why you're having trouble upgrading. Keep in mind the reserved instance is a billing construct and it isn't actually tied directly to that RDS instance. You can spin up another and delete the existing one and the RI will apply to the new one as long as the instance type and licensed (MySQL) match
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u/philsw is correct, the fact it's a reserved instance is irrelevant.
With MySQL and Postgres you can only migrate one major version up, this means you have to upgrade in two steps:
5.5 -> 5.6
5.6 -> 5.7
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Hello.
Reserved Instances provide discounted pricing for specific DB instance types.
Reserved Instances are applied to the "region", "DB engine", "instance type", etc. that match the settings at the time of purchase, so I don't think there is an option to apply them when starting an RDS instance.
https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_WorkingWithReservedDBInstances.html
For example, when you purchase an Oracle t2.micro Reserved Instance, the discount will be automatically applied to the currently running On-Demand Instance t2.micro RDS Oracle.
We recommend that you check the following document for details regarding Reserved Instances.
https://aws.amazon.com/rds/reserved-instances/?nc1=h_ls
To purchase RDS Reserved Instances, follow the steps in the document below.
https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_WorkingWithReservedDBInstances.html#USER_WorkingWithReservedDBInstances.WorkingWith
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That's correct, you specify the instance type that you want to purchase on that page, and once that's complete the instance will appear in the **Reserved Instances** section of the RDS Console. From here you configure storage, backups, etc.
See the section *How To Purchase Reserved Instances* of https://aws.amazon.com/rds/reserved-instances/
Also be aware of the four important bulletpoints in the section *Important Notes about Purchases* at the foot of that page.
AWS re:Post
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Reddit
reddit.com › r/aws › how upgrading rds reserved instances works?
How upgrading RDS reserved instances works? : r/aws
September 10, 2021 - Examples here https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-reserved-instances.html#ri-usage-ex2 ... Thank you but this doesn’t answer my question. The only example they give is getting an instance from another family. I’m just asking changing the size of the same family ... It's family and db engine based for RDS.
Reddit
reddit.com › r/aws › convert an on-demand rds database to reserved
r/aws on Reddit: Convert an on-demand RDS database to reserved
August 22, 2022 -
Hi,
My question is, is it possible to change my already running on-demand priced MySQL database to reserved pricing? I saw some references that it is possible with EC2 instances, but I couldn't find anything similar for RDS.
Thanks!
AWS re:Post
repost.aws › knowledge-center › ec2-modify-reserved-instance
Modify an Amazon EC2 Reserved Instance | AWS re:Post
April 28, 2025 - Use the Amazon EC2 console to modify your existing Reserved Instance. You can modify the instance size of only Linux and UNIX Reserved Instances that don't have a specific license.
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Reserved instances are a billing construct only.
If you buy a reserved instance for a m1.small in us-west-2a, all that means is that one of your on-demand RDS instances that's an m1.small in us-west-2a receives that lower hourly price (and incidentally, if you delete that instance and make a new one, the reservation's lower hourly rate just shifts onto the new instance). No instance is launched by reserving one.
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Think of it as purchasing a licence for one of your existing instances you already have rather than creating a new instance.
N2W Software
n2ws.com › n2ws blog › how-tos › how to modify aws rds instance types
How to Modify AWS RDS Instance Types Using the AWS Console
November 23, 2024 - Learn how to modify the size of RDS instance types manually from medium to micro using the AWS console as well as the AWS CLI.