I’ll introduce how to renew and repurchase AWS EC2 Reserved Instances.
Prerequisite: EC2 Reserved Instances Are Not Auto-Renewed
EC2 Reserved Instances (RIs) are not automatically renewed when the contract period ends. Therefore, you need to purchase new RIs immediately after the contract period expires.
Can I schedule EC2 Reserved Instances to automatically renew?
I have Amazon Elastic Compute Cloud (Amazon EC2) Reserved Instances (RIs) that are about to expire. Can I schedule EC2 RIs to automatically renew?
Resolution You can’t schedule EC2 RIs to automatically renew. To view your active RIs and check their expiration dates, check the Amazon EC2 console. You can set up reservation expiration alerts to notify you when your RIs are approaching expiration.
Note: Reservation expiration alerts don’t automatically renew RIs or purchase new RIs.
EC2 RIs only affect the billing for EC2 instances in your account. When your EC2 RIs expire, your instances won’t shut down or terminate.
There is essentially no Reserved Instance renewal feature, so you need to purchase a Reserved Instance of the same type and availability zone again immediately after the original RI expires. (Depending on timing, some on-demand pricing charges may occur.)Please note that if you purchase a few days before expiration, there will be an overlap period and you may waste one of the purchases for a few days.
Quote from: AWS Developer Forums: EC2 Reserved Instance の更新/再購入タイミングについて …
Response Policy for EC2 Reserved Instance Renewal/Repurchase
Purchase After RI Expiration
Even if an RI expires, it doesn’t mean the instance becomes unavailable; it just gets billed at on-demand rates.
Therefore, as mentioned in the AWS Developer Forums response that “if you purchase a few days before expiration, there will be an overlap period and you may waste one of the purchases for a few days,” I will purchase after expiration.
Register in Task Management Tool
In my case, I registered a task “Purchase RI” in Google Tasks task management tool with the expiration date and time.
AWS also supports reservation expiration alerts, and you can receive alert notifications via email.
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That’s all from the Gemba.