Can Elasticsearch Service RIs be moved across accounts within an organization?

Question

A customer is using the Amazon Elasticsearch Service as a key part of their company's first major AWS project. The lead of the project using Elasticsearch has recently purchased some Reserved Instances (RIs) for both their Prod and Dev clusters.

The customer is now looking into expanding their AWS deployment and using AWS Control Tower to set up a multi-account structure. This may lead them to separate their Prod and Dev Elasticsearch clusters into two different accounts. Once the org structure is set up in Control Tower, is it possible to migrate the RIs to a different account in the same Organization?

Accepted Answer

Suppose Bob and Susan each have an account in an organization. Susan has five Reserved Instances (RIs), and Bob has none. During one particular hour, Susan uses three instances and Bob uses six. This makes nine instances used on the consolidated bill.

AWS bills five as RIs. AWS bills the remaining four as On-Demand instances. Bob receives the cost benefit from Susan's RIs only if he launches his On-Demand instances in the same region where Susan purchased her Reserved Instances.

To receive the cost benefit of Susan’s RIs, Bob also must use the same instance type Susan reserved. For e.g., let's say Susan purchased m4.large.elasticsearch instances in us-west-2. Bob must launch his Amazon Elasticsearch Service domains in us-west-2 with the same instance type to get the cost benefit on the organization's [consolidated bill](https://docs.aws.amazon.com/awsaccountbilling/latest/aboutv2/consolidatedbilling-other.html)

To share an RI or Savings Plans discount with an account, both accounts must have [sharing turned on](https://docs.aws.amazon.com/awsaccountbilling/latest/aboutv2/ri-turn-on-process.html
).

Reference:

[https://docs.aws.amazon.com/awsaccountbilling/latest/aboutv2/ri-turn-off.html](https://docs.aws.amazon.com/awsaccountbilling/latest/aboutv2/ri-turn-off.html
)

Answer

+1 to the above answer, though I'd like to add a bit more context. While Elasticsearch RIs themselves cannot be moved between accounts (within the service console), the discount customer gets from the RI is actually by default shared between accounts in the same AWS Organization. This means that, if the workloads are moved from one account to another, but the corresponding RIs remain on the old account, the default RI sharing behaviour allows the resources from new account to benefit from the RI discount accrued from the old account.

With that said, there is no need to physically move the RIs between the accounts, as they are only relevant as a billing discount that can be still utilized as long as the resources on the new account match the attributes (e.g. region, instance type & size & generation) of the corresponding RI.

Can Elasticsearch Service RIs be moved across accounts within an organization?

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