Reserved instances
Introduction to reserved instance
A Reserved Instance (RI) serves as a discount voucher that offsets pay-as-you-go BCC instance costs with matching configurations while also reserving instance resources. With support for multiple purchase durations, RIs combined with postpaid instances offer greater flexibility compared to traditional subscription-based (prepaid) instances.
Scope of application
RIs can be classified into Availability Zone (AZ)-level and Region-level categories based on their application scope.
| Scope of application | Concepts | Advantages |
|---|---|---|
| Availability Zone-level reserved instances (currently supported) | Once the reserved instance takes effect, it will automatically match and deduct the postpaid BCC instance bills in the same AZ, with the same specification, and EHC clusters (applicable only to EHC-type instances) | Supports resource reservation. Once you purchase a reserved instance, Baidu AI Cloud ensures your account will access postpaid BCC resources that match the RI’s specification and count within the corresponding AZ. |
| Region-level reserved instances (coming soon) | Support deducting bills for postpaid BCC instances with equivalent computing power across all AZs in the Region | Offers flexible automatic cost deduction. |
Bill type
RIs are divided by payment structure into three types: fully prepaid, partially prepaid, and zero prepaid.
Zero prepay and partial prepay payment options are available based on product usage within Baidu AI Cloud. If these payment types are not available in the console, you can submit a support ticket.
| Bill Types | Concepts | Full prepayment |
|---|---|---|
| Full Prepay | When purchasing reserved instances, you pay the entire cost upfront for the computing power over the selected duration, typically aligning with prepaid pricing. This results in the lowest total cost. | Minimum total cost. |
| Partial Prepay | Pay 50% of the cost upfront for the computing power during the purchase period, with the remaining fees deducted hourly for the duration of validity (similar to postpay). This provides a moderate total cost. | Moderate total cost. |
| Zero prepay | No upfront payment is necessary when purchasing reserved instances; fees are deducted hourly during the validity period (similar to postpay), resulting in the highest total cost. | Maximum total cost |
Billing for reserved instances + postpaid instances VS billing for postpaid instances
| Reserved instance + postpaid instance | Postpaid instance | |
|---|---|---|
| Definition | Reserved instances directly reduce bills for postpaid BCC instances. | A bill type for purchasing BCC (pay after using the service), billed by minutes and hours |
| Features | 1. Preferential Price: Lower total cost compared to postpaid instances; 2. Resource Guarantee: AZ-level reserved instances support resource reservation; 3. Flexible Deduction: Reserved instances are not bound to specific instances - one reserved instance can deduct bills for different postpaid BCCs of the same instance family4. Flexible Payment: Support hourly payment (partial or zero prepay) to avoid capital chain pressure from lump-sum payments. | 1. Pay-as-you-go, releasable anytime 2. Higher unit price |
Resource deduction
Upon activation, the reserved instance automatically applies to and deducts charges for pay-as-you-go postpaid BCC instances with matching AZ and instance family. For EHC specifications, the reserved instance auto-matches instances within the same EHC cluster. No extra payment is required for instances deducted. After the reserved instance expires, pay-as-you-go postpaid BCC instances revert to standard billing rates. For example:
Example: A 2c4g instance, postpaid: RMB 1/hour; a 4c8g instance, postpaid: RMB 2/hour. A 2c4g region-level reserved instance with zero prepay: reserved fee RMB 0.7/hour; a 4c8g AZ-level reserved instance with zero prepay: reserved fee RMB 1.4/hour.
The user purchased two 4c8g instances, one 2c4g region-level reserved instance, and one 4c8g AZ-level reserved instance. Since one 4c8g AZ-level reserved instance offsets the cost of one 4c8g instance, the cost for this 4c8g instance becomes RMB 0/hour. The 2c4g region-level reserved instance offsets the 2c4g computing power of the second 4c8g instance, resulting in an additional cost of (2-1)=RMB 1/hour. The total cost becomes the combined cost of the two reserved instances and the remaining 2c4g computing power, calculated as (0.7+1.4+1)=RMB 3.1/hour.