A reserved instance provides a billing discount on your pay-as-you-go Elastic Compute Service (ECS) instances, excluding spot instances. It is not a physical instance. By purchasing a reserved instance, you commit to using ECS for a specific term. In return, you receive a significant discount on the computing resources of matching instances. This lowers your costs and provides flexibility, capacity assurance, and business continuity.
We recommend that you use savings plans instead of reserved instances. Savings plans provide more flexibility and greater discounts than reserved instances. For more information, see What is a savings plan?.
Overview
Quick look
Types of reserved instances
Reserved instances are available in two types: regional reserved instance and zonal reserved instance.
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Regional reserved instance
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You only need to specify a region when you purchase.
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It applies the discount to matching pay-as-you-go instances in any availability zone within the specified region. It also provides flexibility across different instance types within the same instance family.
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It does not provide a resource reservation.
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Zonal reserved instance
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You must specify both a region and an availability zone when you purchase.
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It applies the discount only to pay-as-you-go instances of the same instance type within the specified availability zone.
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It provides a resource reservation. This guarantees that you can launch the specified number of instances of a specific instance type in the designated availability zone at any time during the term.
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The type of reserved instance affects how discounts are matched. For more information, see Matching rules for reserved instances. You can also change the availability zone after purchase. For instructions, see Modify the availability zone of a reserved instance.
Use cases
Consider purchasing reserved instances in the following scenarios to reduce costs for your pay-as-you-go instances while balancing flexibility and savings.
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Scenario |
Benefit |
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You use Auto Scaling to manage ECS instances, have a large number of pay-as-you-go instances, and want to reduce costs. |
By committing to a specific usage term with a reserved instance, you receive a discount, resulting in lower costs compared to using only pay-as-you-go instances. |
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You want to pay for resources in installments to reduce financial pressure. |
Reserved instances support hourly payments (Partial Upfront or No Upfront), helping you avoid the financial pressure of a one-time payment. |
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Your business workloads might move between availability zones, requiring you to release ECS instances in one availability zone and create new ones in another. |
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You use automated operations and maintenance (O&M) to adjust the number of ECS instances based on business demand. |
The discount from a reserved instance applies to any matching pay-as-you-go instance based on its attributes, not a specific instance ID. This provides more flexibility than subscription instances. |
Billing
Payment options
When you purchase a reserved instance, you can choose from the following payment options:
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All Upfront: You pay the entire cost at purchase. No other fees are charged during the term.
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Partial Upfront: You pay a portion of the cost upfront (approximately 50%) and pay the remaining balance in hourly installments throughout the term.
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No Upfront: You make no upfront payment and are billed at a discounted hourly rate throughout the term.
Note-
The Partial Upfront and No Upfront options are available only for terms of one year or longer.
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The availability of the No Upfront option depends on your ECS instance usage. If you cannot see the No Upfront payment option and need to use it, please contact your account manager.
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You are billed for the reserved instance according to your selected payment option for the entire term, regardless of whether it matches any pay-as-you-go instances. To maximize your savings, choose the All Upfront option.
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For the Partial Upfront or No Upfront options, hourly fees are billed by the second and settled by the hour. For pricing details, see the ECS Pricing page.
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Billing rules
After purchase, the reserved instance term begins. Each hour, it automatically matches eligible pay-as-you-go instances and applies a discount to the hourly bill for their computing resources. For information about the matching rules, see Matching rules for reserved instances.
The effective and expiration times are set to the top of the hour. Billing starts from the effective time. For example, if you purchase a one-year reserved instance at 22:45:00 on May 1, 2024, its term and billing start at 22:00:00 on May 1, 2024. The reserved instance expires at 22:00:00 on May 1, 2025. If you already have matching instances, the discount is first applied to the hourly bill from 22:00 to 23:00 on May 1, 2024, and continues until the reserved instance expires.
If you select Specify Effective Time, the term and billing start at the time you specify.
Renewals
To continue receiving discounts, we recommend that you renew your reserved instance before it expires. You can renew a reserved instance either manually or by enabling auto-renewal. You can choose a renewal method at different stages of the reserved instance lifecycle.
Manual renewal
You can manually renew a reserved instance in the ECS console at any time before it expires to extend its term.
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Log on to the Reserved Instances page in the ECS console.
In the upper-left corner of the page, select a region and resource group.
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Find the reserved instance that you want to renew and, in the Actions column, click Renew.
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On the renewal page, select a Renewal Duration of 1 month, 1 year, or 3 years. You can also enable Auto-Renewal if needed. Then, complete the renewal as prompted.
NoteThe availability of the 1-month Renewal Duration option depends on your usage history. If this option is unavailable, you can submit a ticket to request it.
Auto-renewal
After you enable auto-renewal for a reserved instance, it is automatically renewed before it expires. This prevents it from expiring if you forget to renew it manually.
Considerations
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If you manually renew the reserved instance before the automatic renewal date, the system does not perform another renewal in the same billing cycle.
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If you manually renew before the payment is deducted for auto-renewal, the system adjusts the next auto-renewal date based on the new expiration date.
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After you enable auto-renewal, the system makes the first payment deduction attempt 9 days before the expiration date. Ensure your account has a sufficient balance.
NoteIf the first deduction attempt fails, the system retries once per day until the payment is successful or the reserved instance expires.
Procedure
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Find the reserved instance for which you want to enable auto-renewal. In the Actions column, click the
icon and select Auto-Renewal. -
In the dialog box that appears, turn on the Enable Auto-renewal switch, select a Renewal Duration, and then click Confirm.
Refund policy
You can apply for a refund in the following cases:
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You can request a no-questions-asked refund within five days of purchase.
Each Alibaba Cloud account is eligible for one five-day no-questions-asked refund opportunity per year. For example, if you purchase an ECS instance and a reserved instance and use the refund opportunity for the ECS instance, you cannot request another no-questions-asked refund for the reserved instance in the same year.
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Instance capacity is insufficient in the destination region or availability zone after you split, merge, or change the scope of a reserved instance.
Limitations
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Limit |
Description |
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Maximum number of reserved instances |
The limit on the number of reserved instances you can hold depends on the type:
If you need to hold more reserved instances, submit a ticket. |
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Instance type |
The gn6i and t5 instance families do not support regional reserved instances. Reserved instances for these families cannot be split or merged. Note
See the user interface for available instance types. |
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Eligible resources |
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Related documentation
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Before you purchase a reserved instance, we recommend that you understand the matching rules between reserved instances and pay-as-you-go instances. For more information, see Matching rules for reserved instances.
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To learn how to purchase a reserved instance, see Purchase a reserved instance.
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If your workload changes, you can split, merge, or change the availability zone of your reserved instances to match pay-as-you-go instances in different availability zones or of different instance types. For more information, see Split, merge, or modify a reserved instance.
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You can view details about your reserved instances, such as supported instances and normalization factors, as well as billing details, utilization, and coverage. For more information, see View a reserved instance.
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For answers to common questions about reserved instances, see the Instances FAQ.