When your service QPS peak exceeds the clean Queries Per Second (QPS) specification of your Anti-DDoS Proxy instance, you are charged for the excess QPS on a pay-as-you-go basis. This topic describes the billing modes and billing rules for burstable QPS.
Overview
After you purchase an Anti-DDoS Proxy instance, burstable QPS is enabled by default using the daily 95th percentile metering method. If your actual service QPS peak exceeds the clean QPS specification, you are charged for the excess QPS based on actual usage. Burstable QPS flexibly supports traffic growth in the following scenarios. You do not need to upgrade or downgrade your instance in advance, which reduces operational effort:
Holiday sales promotions: large-scale promotions such as Black Friday.
New service launches: launching a new game server or releasing a new product.
Traffic peaks: sudden traffic spikes during specific periods, such as campus course selection systems or government lottery systems.
Proof of concept (POC) users must not exceed their test specifications. Otherwise, unexpected pay-as-you-go bills may be generated.
If the clean QPS specification cannot meet your daily business requirements and you prefer not to use the pay-as-you-go burstable QPS service, upgrade your instance to increase the clean QPS. For more information, see Upgrade instance.
Instance types that support burstable QPS
Anti-DDoS Proxy (Chinese Mainland): Profession and Advanced
Anti-DDoS Proxy (Outside Chinese Mainland): Insurance, Unlimited, Sec-CMA 2.0, Sec-CMA 2.0 (Insurance), Sec-CMA 2.0 (Unlimited), and Sec-CMA
Burstable QPS peak
Formula: Burstable QPS peak = min(Clean QPS × 3, Burstable QPS limit).
NoteThe elastic peak is the upper limit for the elastic resources allocated by default. If your actual usage exceeds the elastic peak, the service is provided on a best-effort basis and you are charged for the elastic resources that you use on a pay-as-you-go basis. However, there is a risk of throttling. To ensure resource reservation beyond the burstable peak, upgrade the clean QPS in advance or contact your account manager for capacity expansion.
Burstable QPS limit:
The Chinese mainland:
IPv4 Anti-DDoS Proxy instance: maximum burstable QPS is 300,000.
IPv6 Anti-DDoS Proxy instance: maximum burstable QPS is 100,000.
Outside the Chinese mainland: maximum burstable QPS is 150,000.
Relationship between burstable QPS and connections
QPS | New connections | Concurrent connections |
0 < QPS ≤ 5,000 | 5,000 | 100,000 |
5,000 < QPS ≤ 10,000 | 10,000 | 200,000 |
10,000 < QPS ≤ 30,000 | 30,000 | 500,000 |
30,000 < QPS ≤ 50,000 | 50,000 | 1,000,000 |
50,000 < QPS ≤ 100,000 | 80,000 | 1,500,000 |
100,000 < QPS ≤ 150,000 | 100,000 | 2,000,000 |
150,000 < QPS ≤ 200,000 Note Supported only by Anti-DDoS Proxy (Chinese Mainland). | 150,000 | 3,000,000 |
200,000 < QPS ≤ 300,000 Note Supported only by Anti-DDoS Proxy (Chinese Mainland). | 200,000 | 4,000,000 |
Billing modes
Starting from 10:00:00 UTC+8 on March 6, 2026, new customers can no longer enable the monthly 95th percentile billing mode for burstable QPS. You also cannot manually adjust burstable QPS settings in the console, including enabling or disabling the feature, changing the billing mode, or modifying the specification. For more information, see [Update] Announcement on changes to the burstable billing feature for Anti-DDoS on March 6, 2026.
Burstable QPS uses pay-as-you-go billing. Two billing modes are supported: the daily 95th percentile metering method and the monthly 95th percentile metering method. The burstable QPS feature takes effect immediately after it is enabled.
You can switch between billing modes. The new mode takes effect at 00:00 on the first day of the next calendar month.
Comparison Item | Daily 95th percentile metering method | Monthly 95th percentile metering method |
Billing method | Billed on a daily basis. Note If you enable burstable QPS for the first time on Day T of a calendar month and select the daily 95th percentile metering method, no fees are generated on Day T. Fees are generated starting from Day T+1, and a bill is generated on Day T+2. | Billed on a monthly basis. |
Billing conditions | Fees are incurred when the daily 95th percentile QPS is greater than the clean QPS. | Fees are incurred when the monthly 95th percentile QPS is greater than the clean QPS. |
Unit price | USD 0.13/QPS/day | USD 1.8/QPS/month |
Billing formula | Burstable QPS fee = (Daily 95th percentile QPS - Clean QPS) × Unit price of the daily 95th percentile metering method. Important If the daily 95th percentile QPS peak exceeds the burstable QPS peak, the service continues to provide protection on a best-effort basis, and you are charged for the burstable QPS on a pay-as-you-go basis. However, there is a risk of throttling. We recommend that you promptly upgrade the clean QPS.
| Burstable QPS fee = (Monthly 95th percentile QPS - Clean QPS) × Validity factor × Unit price of the monthly 95th percentile metering method (USD/QPS/month).
|
Conditions | The daily 95th percentile billing uses the QPS specification from Day T-1 (the day before traffic is generated) as the clean QPS for billing. Therefore, if you upgrade your service QPS specification on a given day, the new specification becomes effective for billing only on the next day. |
|
Billing and settlement
View fee details
You can query and confirm the fee details for burstable QPS on the System Logs page. For more information, see System Logs.
Metering method | Bill generation time | Settlement time |
Daily 95th percentile | The bill for the burstable QPS that is used in a calendar day is displayed on the System Logs page at 10:00 on the next day, and Alibaba Cloud sends notifications to the contacts of your Alibaba Cloud account by email. | At 16:00 on the next day the burstable QPS is used, Alibaba Cloud deducts the fee of the burstable QPS feature from your account balance. |
Monthly 95th percentile | The bill for the burstable QPS that is used in a calendar month is displayed on the System Logs page at 11:00 on the first day of the next month, and Alibaba Cloud sends notifications to the contacts of your Alibaba Cloud account by email. | At 11:00 on the third day of the next month, Alibaba Cloud deducts the fee of the burstable QPS feature from your account balance. |
Billing for overdue payments
If your instance expires but you do not disable the burstable 95th percentile feature, the system stops generating bills.
If you have overdue payments but do not disable the burstable 95th percentile feature, bills continue to be generated.
NoteOverdue payments do not affect the use of subscription instances. However, pay-as-you-go bills continue to be generated.
To resume using burstable QPS, you must pay all outstanding bills and manually re-enable the feature.
Accumulated overdue payments do not affect the use of subscription instances but may affect pay-as-you-go services under your account.
Billing example
An Anti-DDoS Proxy (the Chinese mainland) IPv4 Professional Edition instance has burstable QPS enabled. The billing mode is daily pay-as-you-go. The configuration and traffic details for each day are as follows:
January 1: Service QPS specification is 3,000 QPS.
January 2: Service QPS specification is upgraded from 3,000 QPS to 4,000 QPS. The actual QPS peak for the day is 6,000 QPS.
January 3: Actual daily QPS peak is 6,000 QPS.
January 4: Actual daily QPS peak is 15,000 QPS.
The billing formula for burstable QPS is as follows: Burstable QPS Fee = (Actual Peak QPS - Clean QPS) × Corresponding Daily Unit Price(USD/day/QPS).
The daily 95th percentile billing uses the QPS specification from Day T-1 (the day before traffic is generated) as the clean QPS for billing. Therefore, if you upgrade your service QPS specification on a given day, the new specification becomes effective for billing only on the next day.
Billing on January 3 (calculates burstable QPS fee for January 2)
Service QPS specification on T-1 (January 1) = 3,000 QPS.
Actual QPS peak on January 2 = 6,000 QPS.
Burstable QPS fee = (6,000 - 3,000) QPS × USD 0.13/QPS/day = USD 390.
Billing on January 4 (calculates burstable QPS fee for January 3):
Service QPS specification on T-1 (January 2) = 4,000 QPS.
Actual QPS peak on January 3 = 6,000 QPS.
Burstable QPS fee = (6,000 - 4,000) QPS USD 0.13/QPS/day = USD 260.
Billing on January 5 (calculates burstable QPS fee for January 4):
Service QPS specification on T-1 (January 3) = 4,000 QPS.
Actual QPS peak on January 4 = 14,000 QPS.
NoteThis exceeds the burstable QPS peak = min(4,000 × 3, 300,000) = 12,000 QPS. However, the system still tries to process requests and bills you for the actual QPS peak of 14,000.
Burstable QPS fee = (14,000 - 4,000) QPS ×USD 0.13/QPS/day = USD 1,300.