A reserved instance serves as a paid membership card for pay-as-you-go Elastic Compute Service (ECS) instances (excluding preemptible instances). Similar to other membership cards, a reserved instance can offset the fees of the pay-as-you-go ECS instances whose attributes match the attributes of the reserved instance. After you purchase reserved instances, you commit to using pay-as-you-go instances for a specific period of time. The reserved instances can provide benefits to your business. For example, you can significantly reduce the costs of the computing resources of pay-as-you-go instances and achieve instance flexibility, resource assurance, and business continuity.
We recommend that you use savings plans instead of reserved instances. Savings plans provide more flexibility and discounts than reserved instances. For more information, see Savings plans.
Overview of reserved instances
Get started with reserved instances
Reserved instance types
Reserved instances are classified into regional and zonal reserved instances.
Regional reserved instances
You need to only specify a region when you purchase a reserved instance.
A regional reserved instance can be used to offset eligible pay-as-you-go instances across zones within a single region and across different instance types within the same instance family.
Resource reservation is not supported.
Zonal reserved instances
You must specify the region and zone when you purchase a zonal reserved instance.
Only the fees of pay-as-you-go instances of the same instance type in a single zone can be offset by a zonal reserved instance.
Resource reservation is supported. A specific number of instances of a specified instance type are reserved within the validity period. This ensures that pay-as-you-go instances can be created in the specified zone at any time.
The type of the reserved instance affects the matching conditions. For more information, see Usage rules for reserved instances. After you purchase a reserved instance, you can change the zone based on your business requirements. For more information, see Change the zone of a reserved instance of the "Split, merge, or modify reserved instances" topic.
Use scenarios
The following table describes the scenarios in which you can purchase reserved instances to offset the bills of pay-as-you-go instances to ensure business flexibility and reduce costs.
Scenario | Benefit |
You use Auto Scaling to manage ECS instances and have a large number of pay-as-you-go instances. You want to reduce your costs. | After you purchase reserved instances, you commit to using pay-as-you-go instances for a specific period of time. Reserved instances provide significant discounts compared with pay-as-you-go instances. |
You want to pay for resources in installments to mitigate financial pressure. | You can pay by hour by selecting the Partial Upfront or No Upfront payment option to relieve the financial pressure caused by all upfront payments. |
If you want to change the region for your business, you must release ECS instances in the original zone and create ECS instances in the zones of the destination region. |
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During automated O&M, the number of instances can be automatically adjusted. | Purchased reserved instances deliver computing power instead of specific instances. Reserved instances can be matched to eligible pay-as-you-go instances and provide more flexibility than subscription instances. |
Billing
Payment options
Reserved instances support the following payment options:
All Upfront: Full payment is required at the time of purchase. No additional costs or hourly fees are charged within the term of the reserved instance.
Partial Upfront: Partial payment (approximately 50% of the full amount) is required upfront at the time of purchase. The remainder is paid at a discounted hourly rate throughout the term.
No Upfront: No upfront payment is required at the time of purchase. You are billed a discounted hourly rate every hour throughout the term.
NoteTo use the Partial Upfront or No Upfront payment option, make sure that the term of the reserved instance is longer than one year.
Your ECS usage determines whether you can use the No Upfront payment option. If you cannot find the No Upfront payment option and you want to use the option, submit a ticket.
You are charged based on the payment option that you selected, regardless of whether the reserved instance is matched to pay-as-you-go instances. The All Upfront option is the most cost-effective.
If the Partial Upfront or No Upfront option is selected, the hourly fee is calculated on a per-second basis, and the bill is generated on an hourly basis and paid on a monthly basis. For information about the pricing of reserved instances, see the Pricing tab of the Elastic Compute Service product page. If the total payable amount on the monthly bill reaches USD 1,000, USD 1,000 is automatically deducted from your account balance. Fees less than USD 1,000 are included in the monthly bill.
Billing rules
A reserved instance immediately takes effect after it is purchased, and matches eligible pay-as-you-go instances on an hourly basis to offset the bills of the pay-as-you-go instances. For information about how a reserved instance is matched to pay-as-you-go instances, see Usage rules for reserved instances.
A reserved instance takes effect and is billed starting on the hour of purchase. The reserved instance expires at 24:00:00 on the expiration date. For example, if you purchase a reserved instance with a one-year term at 22:45:00 on May 1, 2024, the reserved instance takes effect and is billed starting 22:00:00 on May 1, 2024. The reserved instance expires at 00:00:00 on May 2, 2025. If you purchase a reserved instance and have pay-as-you-go instances that match the attributes of the reserved instance, the reserved instance is applied to offset the bills of the matching pay-as-you-go instances starting from 22:00 to 23:00 on May 1, 2024 until the reserved instance expires.
Configure the Specify Effective Time parameter. Billing for a reserved instance starts at the effective time that you specify for the reserved instance.
Renewal
To continue benefiting from the billing discounts provided by reserved instances, we recommend that you renew reserved instances to extend the related terms before the reserved instances expire. Reserved instances support the following renewal methods: manual renewal and auto-renewal. Select a renewal method based on the lifecycle state of your reserved instance.
Manual renewal
You can manually renew a reserved instance in the ECS console at any time before the reserved instance expires.
Go to the Reserved Instances page.
Log on to the ECS console.
In the left-side navigation pane, choose Deployment & Elasticity >
> Reserved Instances. In the top navigation bar, select the region and resource group to which the resource belongs.
Find the reserved instance that you want to renew and click Renew.
On the Renew page, set Renewal Duration to 1 month, 1 year, or 3 years, select Enable Auto-renewal based on your business requirements, and then complete the renewal as prompted.
Auto-renewal
If auto-renewal is enabled for a reserved instance, the reserved instance is automatically renewed before it expires. You can enable this feature for reserved instances to prevent the reserved instances from being automatically released.
Considerations
If you manually renew a reserved instance before it is automatically renewed, the auto-renewal operation is not performed during the current billing cycle.
If you manually renew a reserved instance before the auto-renewal payment is deducted, the system renews the reserved instance based on the new expiration date.
Starting on the ninth day before the instance expires, Alibaba Cloud attempts to deduct the renewal payment from your account. Make sure that your account balance is sufficient.
NoteIf the first deduction attempt fails, the system attempts to deduct the renewal payment once every day until the payment is deducted or until the reserved instance expires.
Procedure
Go to the Reserved Instances page.
Log on to the ECS console.
In the left-side navigation pane, choose Deployment & Elasticity >
> Reserved Instances. In the top navigation bar, select the region and resource group to which the resource belongs.
Find the reserved instance that you want to renew and click Auto-renewal in the Actions column.
Read the notes, turn on Enable Auto-renewal, select a value for the Renewal Period parameter, and then click OK.
Limits
Item | Description |
Maximum number of reserved instances | The maximum number of reserved instances varies based on the type of reserved instances.
If you require more reserved instances, submit a ticket. |
Instance type | The gn6i and t5 instance families do not support regional reserved instances. The gn6i and t5 reserved instances cannot be split or merged. Note The instance types that you can select when you purchase a reserved instance are displayed on the page. |
Eligible resources |
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References
Before you purchase reserved instances, we recommend that you understand the deduction rules for reserved instances and pay-as-you-go instances. For more information, see Usage rules for reserved instances.
For information about how to purchase reserved instances, see Purchase reserved instances.
If your workloads change, you can split or merge reserved instances or change the zones of reserved instances to match pay-as-you-go instances of different instance types and zones. For more information, see Split, merge, or modify reserved instances.
You can view information about a reserved instance, such as the ECS instances whose bills can be offset by the reserved instance and the normalization factor of the reserved instance. You can also view the billing details, utilization, and coverage rate of the reserved instance. For more information, see View reserved instances.
For information about frequently asked questions about reserved instances, see Instance FAQ.