When your service QPS peak exceeds the clean QPS specification of an Anti-DDoS Proxy instance, burstable QPS generates pay-as-you-go fees based on actual usage. This topic describes the billing modes and billing rules of burstable QPS.
Overview
After you purchase an Anti-DDoS Proxy instance, burstable QPS is enabled by default in daily 95th percentile mode. If your actual service QPS peak exceeds the clean QPS specification, you are charged for the excess QPS based on actual usage. Burstable QPS adapts to traffic growth in the following scenarios without advance upgrades or downgrades, which reduces operational overhead:
Holiday sales promotions: large-scale promotional events such as Black Friday.
New service launches: for example, opening a new game server or releasing a new product.
Traffic peaks: for example, campus course selection systems or government lottery systems that receive sudden traffic spikes during specific periods.
If you are a proof of concept (POC) user, do not exceed your test specifications. Otherwise, pay-as-you-go bills are generated.
If the clean QPS specification cannot meet your daily business requirements and you do not want to use the pay-as-you-go burstable QPS service, upgrade your instance to increase the clean QPS. For instructions, see Upgrade an 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 1.0
Burstable QPS peak
Formula: Burstable QPS peak = min(Clean QPS × 3, Burstable QPS limit).
NoteThe burstable peak is the upper limit of the burstable resources allocated by default. If your actual usage exceeds the burstable peak, the service continues on a best-effort basis and burstable pay-as-you-go fees are generated based on actual usage. However, packet loss may occur while the cluster scales out. Promptly upgrade the clean QPS.
Burstable QPS limit:
The Chinese mainland:
IPv4 Anti-DDoS Proxy instance: the maximum burstable QPS is 300,000.
IPv6 Anti-DDoS Proxy instance: the maximum burstable QPS is 100,000.
Outside the Chinese mainland: the 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 |
New protection plans
The Global and Outside Chinese Mainland plans support burstable QPS. The Global Partner plan does not use burstable pay-as-you-go billing. When your service QPS exceeds the purchased specification, requests are throttled.
Instances | Daily 95th percentile unit price | Monthly 95th percentile unit price |
Global and Outside Chinese Mainland (newly purchased plans) | USD 0.13/day/QPS | The monthly 95th percentile mode is not available for newly purchased instances |
Chinese Mainland plans and legacy Outside Chinese Mainland plans | USD 0.13/day/QPS | USD 2.25/month/QPS |
Instances purchased after March 6, 2026 support only the daily 95th percentile mode. The monthly 95th percentile prices apply only to existing instances that still use that mode.
Billing modes
Starting from 10:00:00 UTC+8 on March 6, 2026, new customers can no longer use the burstable QPS monthly 95th percentile billing mode. You can also no longer manually adjust burstable QPS settings in the console, including disabling or enabling the feature, changing the billing mode, and changing the specification. For more information, see [Important] Adjustments to Anti-DDoS burstable billing feature.
Burstable QPS uses pay-as-you-go (postpaid) billing and supports two billing modes: the daily 95th percentile mode and the monthly 95th percentile mode. Burstable QPS takes effect immediately after it is enabled.
You can switch between billing modes. A switch takes effect at 00:00 on the first day of the next month.
Item | Daily 95th percentile mode | Monthly 95th percentile mode |
Settlement method | Settled by calendar day. Note If you enable burstable QPS for the first time on day T of a calendar month and select the daily 95th percentile mode, no fees are generated on day T. Fees start to accrue on day T+1, and a bill is generated on day T+2. | Settled by calendar month. |
Billing conditions | Daily 95th percentile QPS peak > clean QPS: fees are generated. | Monthly 95th percentile QPS peak > clean QPS: fees are generated. |
Unit price | USD 0.13/day/QPS | USD 2.25/month/QPS |
Billing formula | Burstable QPS fee = (daily 95th percentile QPS peak - clean QPS) × the unit price of the daily 95th percentile mode. Important Daily 95th percentile QPS peak exceeds the Burstable QPS peak: the service continues on a best-effort basis and burstable pay-as-you-go fees are generated based on actual usage. However, packet loss may occur while the cluster scales out. Promptly upgrade the clean QPS.
| Burstable QPS fee = (monthly 95th percentile QPS peak - clean QPS) × validity factor × the unit price of the monthly 95th percentile mode (USD/month/QPS).
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Limits | Daily 95th percentile billing uses the QPS specification of day T-1 (the day before the traffic is generated) as the clean QPS. Therefore, if you upgrade the service QPS specification on a given day, the new specification takes effect as the billing baseline only in the bill of the next day. |
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Billing and settlement
View fee details
You can query and confirm the fee details of burstable QPS on the System Logs page. For instructions, see System logs.
Billing mode | Bill generation time | Settlement time |
Daily 95th percentile | At 10:00 the next day, Anti-DDoS Proxy pushes the elastic QPS bill for the previous calendar day through the System Logs page, and sends a billing notification to the contact of your Alibaba Cloud account via email. | At 16:00 the next day, Alibaba Cloud deducts the corresponding fee from your account balance. |
Monthly 95th percentile | Before 10:00 on the first day of the next month, Anti-DDoS Proxy pushes the elastic QPS bill for the previous calendar month through the System Logs page, and sends a billing notification to the contact of your Alibaba Cloud account via email. | At 11:00 on the third day of the next month, Alibaba Cloud deducts the corresponding fee from your account balance. |
Billing for overdue payments
If your instance expires and you do not disable the burstable 95th percentile feature, the system stops reporting usage and no more bills are generated.
If you have an overdue payment and do not disable the burstable 95th percentile feature, bills continue to be generated.
NoteOverdue payments do not affect the use of subscription instances, but pay-as-you-go bills continue to be generated.
Billing example
An Anti-DDoS Proxy (Chinese Mainland) IPv4 Professional Edition instance has burstable QPS enabled, and the billing mode is daily pay-as-you-go. The daily configuration and traffic are as follows:
January 1: the service QPS specification is 3,000 QPS.
January 2: the service QPS specification is upgraded from 3,000 QPS to 4,000 QPS. The actual QPS peak of the day is 6,000 QPS.
January 3: the actual daily QPS peak is 6,000 QPS.
January 4: the actual daily QPS peak is 15,000 QPS.
Based on the billing formula: burstable QPS fee = (actual QPS peak - service QPS) × the applicable daily unit price (USD/month/QPS).
Daily 95th percentile billing uses the QPS specification of day T-1 (the day before the traffic is generated) as the clean QPS. Therefore, if you upgrade the service QPS specification on a given day, the new specification takes effect as the billing baseline only in the bill of the next day.
Bill generated on January 3 (calculates the burstable QPS fee for January 2)
The service QPS specification on day T-1 (January 1) = 3,000 QPS.
The actual QPS peak on January 2 = 6,000 QPS.
Burstable QPS fee = (6,000 - 3,000) QPS × USD 0.13/day/QPS = USD 390.
Bill generated on January 4 (calculates the burstable QPS fee for January 3):
The service QPS specification on day T-1 (January 2) = 4,000 QPS.
The actual QPS peak on January 3 = 6,000 QPS.
Burstable QPS fee = (6,000 - 4,000) QPS × USD 0.13/day/QPS = USD 260.
Bill generated on January 5 (calculates the burstable QPS fee for January 4):
The service QPS specification on day T-1 (January 3) = 4,000 QPS.
The 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 provides the service on a best-effort basis and bills you based on the actual QPS peak of 14,000.
Burstable QPS fee = (14,000 - 4,000) QPS × USD 0.13/day/QPS = USD 1,300.