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Anti-DDoS:Billing of the burstable QPS feature

Last Updated:Jul 19, 2025

If your service's queries per second (QPS) is stable in most cases with spikes occurring only in specific scenarios such as large-scale promotions or service releases, you can set the clean QPS to a value that meets your daily business requirements when purchasing an Anti-DDoS Proxy instance. Then, you can enable the burstable QPS feature to prevent packet loss or rate limiting caused by QPS spikes. This topic describes the billing of the burstable QPS feature provided by Anti-DDoS Proxy.

Scenarios

After you add services to your Anti-DDoS Proxy instance, the peak service QPS may exceed the clean QPS that you selected when purchasing the instance. In this case, random packet loss occurs during service traffic forwarding. If the peak service QPS remains higher than the clean QPS for a long period, rate limiting is triggered, affecting access to your services. The following list describes scenarios where peak service QPS exceeds clean QPS and provides solutions:

  • The clean QPS of your instance cannot meet your business requirements, and you want to upgrade the instance to increase the clean QPS. For more information, see Upgrade an instance.

  • The clean QPS of your instance can meet your daily business requirements but cannot handle QPS spikes. In this case, we recommend that you enable the burstable QPS feature. Examples include the following:

    • Holiday promotions such as Black Friday.

    • Release of services, such as launch of a new gaming server or new product.

    • Sharp increase in access requests to websites, such as requests to online course selection systems and government lottery systems within a specific period

    With the burstable QPS feature enabled, if your service QPS exceeds the clean QPS but stays below the burstable QPS, the Anti-DDoS Proxy instance will handle the traffic normally with pay-as-you-go charges. If your service QPS remains within the clean QPS, no additional charges apply.

Important

If you want to perform proof of concept (POC) tests, we recommend that you do not enable the burstable QPS feature. If you enable the burstable QPS feature, you are charged for the feature on a pay-as-you-go basis.

Limits

After enabled, the burstable QPS can be up to three times the clean QPS, but cannot exceed the following limits. If your clean QPS already exceeds these limits, burstable QPS cannot be enabled:

  • Anti-DDoS Proxy (Chinese Mainland): Burstable QPS for instances using IPv4 addresses is capped at 300,000, burstable QPS for instances using IPv6 addresses is capped at 100,000.

  • Anti-DDoS Proxy (Outside Chinese Mainland): Burstable QPS is capped at 150,000.

Supported instances

  • Anti-DDoS Proxy (Chinese Mainland): Profession and Advanced mitigation plans

  • Anti-DDoS Proxy (Outside Chinese Mainland): Insurance, Unlimited, Secure Chinese Mainland Acceleration (Sec-CMA), and Sec-CMA (Basic) mitigation plans

Mappings between burstable QPS and connections

QPS

Number of new connections

Number of 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

Only supported by Anti-DDoS Proxy (Chinese Mainland).

150,000

3,000,000

200,000 < QPS ≤ 300,000

Note

Only supported by Anti-DDoS Proxy (Chinese Mainland).

200,000

4,000,000

Billing methods

Important

The burstable QPS feature takes effect immediately after you enable it.

The burstable QPS feature uses the pay-as-you-go billing method. You can use either the daily 95th percentile bandwidth or the monthly 95th percentile bandwidth metering method. You can switch between these methods, and the new method takes effect from 00:00 on the first day of the next month.

Item

Daily 95th percentile

Monthly 95th percentile

Billing cycle

You are charged for usage on a calendar day.

Important

If you enable the burstable QPS feature for the first time on Day T in a calendar month and select the daily 95th percentile metering method, you are not charged for usage on Day T. On Day T+1, you are charged for the burstable QPS usage. On Day T+2, the bill for the burstable QPS used on Day T+1 is generated.

You are charged for usage on a calendar month.

Billing conditions

If the daily 95th percentile QPS is greater than the clean QPS, you are charged for the burstable QPS feature.

How to calculate the daily 95th percentile QPS:

Collect the service QPS values of your instance every 5 minutes on a calendar day. On a calendar day, 288 QPS values can be collected. Exclude the QPS values collected during DDoS attacks. Then, sort the remaining QPS values in descending order and exclude the top 5 QPS values. The largest QPS value among the remaining QPS values is used as the daily 95th percentile QPS.

If the monthly 95th percentile QPS is greater than the clean QPS, you are charged for the burstable QPS feature.

The following describes how to calculate the monthly 95th percentile QPS:

  1. Obtain the daily peak QPS: Collect the service QPS values of your instance every 5 minutes in a calendar day. In a calendar day, 288 QPS values can be collected. Exclude the QPS values collected during DDoS attacks. The largest QPS value among the remaining QPS values is used as the daily peak QPS.

  2. Calculate the monthly 95th percentile QPS: Sort the collected daily peak QPS values in a calendar month in descending order and calculate the average value of the top 5 daily peak QPS values. The average value is used as the monthly 95th percentile QPS.

Unit price

USD 0.13 per QPS per day

USD 1.8 per QPS per month

Billing formula

Fee of the burstable QPS = Metered usage for the daily 95th percentile QPS × Unit price when the daily 95th percentile metering method is used.

Metered usage for the daily 95th percentile QPS = min (Daily 95th percentile QPS, Burstable QPS) - Clean QPS.

Important

If the daily 95th percentile QPS exceeds the burstable QPS, the service may be throttled. We recommend that you upgrade the clean QPS of your instance.

Fee of the burstable QPS = Metered usage for the monthly 95th percentile QPS × Effective factor × Unit price when the monthly 95th percentile metering method is used (USD/month/QPS).

  • Metered usage for the monthly 95th percentile QPS = min (Monthly 95th percentile QPS, Burstable QPS) - Clean QPS.

    The clean QPS is the value on the last day of the calendar month in which the burstable QPS feature is enabled.

    Important

    If the monthly 95th percentile QPS exceeds the burstable QPS, the service may be throttled. We recommend that you upgrade the clean QPS of your instance.

  • Effective factor = Number of valid days in a calendar month ÷ Total number of days in the calendar month.

    Important

    If you enable the burstable QPS feature for the first time on Day T in a calendar month and select the monthly 95th percentile metering method, Day T is not included in the valid days of the feature.

    For example, if you enable the burstable QPS feature on July 15, 2024, and do not disable it in July, the valid days in July are from July 16 to July 31, totaling 16 days. The total number of days in July is 31. The effective factor is 16 ÷ 31 = 0.51612903.

Limits

  • The daily 95th percentile metering method can be disabled only once within a calendar month.

  • You cannot change the metering method on the last day of a calendar month.

  • The monthly 95th percentile metering method can be disabled only once in a calendar month.

  • You cannot change the metering method on the last day of a calendar month.

How to enable the burstable QPS feature

  • You can activate the burstable QPS feature during the purchase of an Anti-DDoS Proxy instance by selecting the 95th percentile burstable QPS mode on the purchase page. For more information, see Purchase an Anti-DDoS Proxy instance.

  • If you did not enable the burstable QPS feature when you purchased an Anti-DDoS Pro instance, you can go to the Instances page of the Anti-DDoS Pro console to enable the feature. For more information, see Configure burstable QPS.

Bill generation and settlement time

You can query and confirm the billing details of the burstable QPS feature on the System Logs page. For more information, see Query 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 example

For instance, if you enable the burstable QPS feature from March 1 to March 6 using the monthly 95th percentile metering method, the statistics chart will reflect the QPS trend for that period. The clean QPS is 3000, and the burstable QPS is 9000.

Note

The statistics chart only shows data for the duration when the burstable QPS feature is active.

image..png

Fee of the burstable QPS = Metered usage for the monthly 95th percentile QPS × Effective factor × Unit price for the monthly 95th percentile QPS (USD/month/QPS).

  1. Calculating the monthly 95th percentile QPS metering value

    The metered usage for the monthly 95th percentile QPS = 8000 - 3000 (the clean QPS on the last day of the calendar month when the burstable QPS feature is active) = 5000.

  2. Calculate the effective factor

    Effective factor = 6 (number of valid days in the calendar month) ÷ 31 (total days in the calendar month) = 0.19354839

  3. Identify the unit price for the burstable QPS

    The unit price for the monthly 95th percentile metering method is 1.8 USD per month per QPS.

Therefore, the charge for your burstable QPS is 5000 × 0.19354839 × 1.8 = 1,741.9355 USD.

References