Operation Scope
This document details the fee calculation rules for configuration changes of TencentDB for MongoDB instances under both pay-as-you-go and yearly/monthly subscription billing modes.
Replica set instances
A configuration change refers to an adjustment to the computing specifications of Mongod nodes, including node memory, disk capacity, and the number of primary/secondary nodes. Any configuration item change will affect subsequent fee settlement.
Shard instances
Configuration changes include two parts: Mongod and Mongos.
Mongod: involves shard quantity, the number of nodes per shard, and the memory and storage capacity of a single node.
Mongos: involves computing specifications, memory, and the number of nodes.
Fees will be recalculated when any of the above configuration items is changed.
Pay-as-You-Go
|
Settlement for the old specification | After the configuration is changed, the billing system immediately settles the fees of the old specification. Billing rules: Fees are calculated based on the actual usage duration, and any portion less than one hour is billed as one hour. Settlement price: determined by the pricing tier corresponding to the actual usage duration of the old specification. For specific billing prices, see Product Pricing. If the duration is greater than 0 days and less than or equal to 4 days, the first-tier pay-as-you-go pricing applies. If the duration is greater than 4 days and less than or equal to 15 days, the second-tier pay-as-you-go pricing applies. If the duration is greater than 15 days, the third-tier pay-as-you-go pricing applies. |
Rebilling at the new specification | After the configuration is changed, the billing system restarts billing from the time of change and immediately starts billing based on the new specifications. Billing rules: The system settles fees at every full hour (UTC+8). Tiered pricing: Billing for the new specification restarts from the first tier of pay-as-you-go pricing. For specific billing prices, see Product Pricing. |
Yearly/Monthly Subscription
|
Configuration Upgrade |
Calculate price difference
| Billing calculates the difference between the remaining value of the new configuration and the remaining value of the original configuration, and deducts the corresponding amount from your account balance. |
| Subsequent renewal | After the configuration upgrade is successful, the next renewal cycle will be billed directly based on the new, higher instance specifications. |
Configuration Downgrade | Calculate refund | When the instance specifications are downgraded, the system calculates the refund based on the remaining value: Refund amount = Remaining value of the original configuration - Purchase value of the new configuration Remaining value of the original configuration = Valid order amount of the original configuration - Used value of the original configuration Effective order amount of the original configuration: The actual paid amount of an active order, including discounts and vouchers. Used value of the original configuration: For a full month: Fees are deducted based on the yearly/monthly subscription price and the corresponding official website discount. For a partial month: Fees are deducted based on the pay-as-you-go tiered pricing for the used duration. Purchase value of the new configuration = Current official price of the new configuration × Remaining usage duration Note: 1. The system will calculate fees based on the currently effective discount. 2. Used deduction vouchers or promo vouchers are not refundable. 3. The refund amount will be returned to your account in proportion to the original payment methods (cash and free credit). 4. If the calculated refund amount is less than or equal to 0, it will be processed as 0, meaning no refund will be issued. |
| Subsequent renewal | After the downgrade is successful, the next renewal cycle will be billed based on the new, lower instance specifications. |
Refund Example
On March 1, 2025, Enterprise A purchased a MongoDB replica set in Guangzhou Zone 3 with high IO 10-gigabit type, 2 cores and 4 GB of memory, and a 200 GB disk.
Unit price: 125.58 USD/month.
Discount description: For a 1-year purchase, you can enjoy a 17% discount with yearly subscription.
The total payment amount is: 125.58 × 12 × 0.83 = 1,250.78 (USD).
Scenario 1
On May 1, 2025, you need to downgrade the MongoDB replica set that has been used for 2 months with high IO 10-gigabit type, 2 cores and 4 GB of memory, and a 200 GB disk to 2 cores and 4 GB of memory with a 100 GB disk.
Discount description: No discount is offered for a 2-month subscription, while a 6- to 11-month subscription can enjoy a 12% discount.
Unit price of the new configuration: 95.58 USD/month.
Billing formula:
Remaining value of the original configuration = Valid order amount of the original configuration - Used value of the original configuration = 1,250.78 - 125.58 × 2 = 999.62 (USD)
Purchase value of the new configuration = Current official price of the new configuration × Remaining usage duration = 95.58 × 10 × 0.88 = 841.10 (USD)
Refund amount for instance configuration downgrade = Remaining value of the original configuration - Purchase value of the new configuration = 999.62 - 841.10 = 158.52 (USD).
Scenario 2
On November 1, 2025, you need to downgrade the MongoDB replica set that has been used for 8 months with high IO 10-gigabit type, 2 cores and 4 GB of memory, and a 200 GB disk to 2 cores and 4 GB of memory with a 100 GB disk.
Discount description: A 6- to 11-month subscription can enjoy a 12% discount, and this discount applies if the subscription has been used for 8 months.
Unit price of the new configuration: 95.58 USD/month.
Billing formula:
Remaining value of the original configuration = Valid order amount of the original configuration - Used value of the original configuration = 1,250.78 - 125.58 × 8 × 0.88 = 1,250.78 - 884.08 = 366.70 (USD)
Purchase value of the new configuration = Current official price of the new configuration × Remaining usage duration = 95.58 × 4 = 382.32 (USD)
Refund amount for instance configuration downgrade = Remaining value of the original configuration - Purchase value of the new configuration = 366.70 - 382.32 = -15.62 (USD)
If the refund amount is less than or equal to 0, it is calculated as 0, meaning the refund amount is 0.
Scenario 3
On November 15, 2025, you need to downgrade the MongoDB replica set that has been used for 8 months and 15 days with high IO 10-gigabit type, 2 cores and 4 GB of memory, and a 200 GB disk to 2 cores and 4 GB of memory with a 100 GB disk.
Discount description: A 6- to 11-month subscription can enjoy a 12% discount, and this discount applies if the subscription has been used for 8 months.
Unit price of the new configuration: 95.58 USD/month. Hourly unit price of the original configuration: 0.17 (USD/GB/hour)
Billing formula:
Remaining value of the original configuration = Valid order amount of the original configuration - Used value of the original configuration = 1,250.78 - 125.58 × 8 × 0.88 - 0.17 × 24 × 15 × 0.8 = 1,250.78 - 884.08 - 48.96 = 317.74 (USD)
Purchase value of the new configuration = Current official price of the new configuration × Remaining usage duration = 95.58 × 3 + 0.17 × 24 × 15 = 286.74 + 61.20 = 347.94 (USD)
Refund amount for instance configuration downgrade = Remaining value of the original configuration - Purchase value of the new configuration = 317.74 - 347.94 = -30.20 (USD)
If the refund amount is less than or equal to 0, it is calculated as 0, meaning the refund amount is 0.