How to enable burstable QPS - Web Application Firewall - Alibaba Cloud Documentation Center

If you experience short-term or sudden traffic spikes, such as during a sales promotion, your queries per second (QPS) may exceed the total purchased QPS (the sum of the QPS included in your instance edition and any purchased QPS extensions). You can enable burstable QPS to handle the excess traffic. This feature bills you for the overage on a pay-as-you-go basis, prevents your instance from being sandboxed, and ensures your services are not interrupted. This feature is available only for subscription instances. This topic describes how to enable burstable QPS.

Use cases

During major business promotions, you may face unpredictable QPS spikes that are difficult to forecast. Instead of manually scaling your instance specifications, enable burstable QPS to handle these spikes and reduce operational overhead.

Billing

Scenario 1: Daily peak QPS is less than or equal to your purchased QPS (the sum of edition QPS and extension QPS).
Your instance is billed based on your subscription. For more information, see Subscription.
Scenario 2: Daily peak QPS exceeds your purchased QPS (the sum of edition QPS and extension QPS), and burstable QPS is disabled (default).
Your instance is handled by the standard QPS overage and sandbox mechanism. For more information about the sandbox, see Sandbox overview.

Scenario 3: Daily peak QPS exceeds your purchased QPS (the sum of edition QPS and extension QPS), and burstable QPS is enabled.

Excess QPS is billed on a pay-as-you-go basis.

Excess QPS	Billable item	Billing cycle	Formula (Unit: USD)
≤ burstable QPS (the value you set when you enable burstable QPS)	Excess QPS over the purchased limit Request processing fee: Basic traffic: Chinese mainland: USD 0.02/QPS/day Outside the Chinese mainland: USD 0.03/QPS/day bot management or API security enabled: Chinese mainland: USD 0.035/QPS/day Outside the Chinese mainland: USD 0.045/QPS/day Both bot management and API security enabled: Chinese mainland: USD 0.05/QPS/day Outside the Chinese mainland: USD 0.06/QPS/day	Fees are settled daily (UTC+8). A new billing cycle starts after settlement.	Daily fee = (Daily peak QPS - Purchased QPS) × Request processing fee
> burstable QPS, and the instance has not entered the sandbox on that day (the number of overage events is three or fewer).	Burstable QPS Request processing fee: Basic traffic: Chinese mainland: USD 0.02/QPS/day Outside the Chinese mainland: USD 0.03/QPS/day bot management or API security enabled: Chinese mainland: USD 0.035/QPS/day Outside the Chinese mainland: USD 0.045/QPS/day Both bot management and API security enabled: Chinese mainland: USD 0.05/QPS/day Outside the Chinese mainland: USD 0.06/QPS/day		Daily fee = burstable QPS × Request processing fee Note An overage event is recorded when the peak QPS exceeds the WAF specification threshold for five consecutive minutes. An instance enters the sandbox on the fourth overage event of the day.
> burstable QPS, and the instance has entered and remains in the sandbox on that day.	No fees are charged for the day.		N/A

Billing examples

This example uses the pricing for the Chinese Mainland. Assume that you have a Chinese Mainland Chinese Mainland Chinese Mainland Chinese Mainland that includes 10,000 QPS, and you have purchased a QPS extension of 50,000 QPS. You also have Chinese Mainland enabled. If the daily peak traffic reaches 64,000 QPS, the excess QPS is 4,000 QPS (64,000 - 10,000 - 50,000).

If you have enabled burstable QPS with a limit of 5,000 QPS.
In this scenario, the excess QPS is less than the configured burstable QPS limit. The request processing fee with bot management enabled is USD 0.035/QPS/day. The total fee is USD 140 (4,000 × 0.035).
If you have enabled burstable QPS with a limit of 1,250 QPS.
In this scenario, the excess QPS is greater than the configured burstable QPS limit. The request processing fee with bot management enabled is USD 0.035/QPS/day. The total fee is USD 43.75 (1,250 × 0.035).
Important
- An overage event is recorded when the peak QPS exceeds the WAF specification threshold for five consecutive minutes. An instance enters the sandbox on the fourth overage event of the day.
- An instance in the sandbox is no longer covered by the Service Level Agreement (SLA). Traffic to a sandboxed instance may experience issues such as packet loss, rate limiting, connection limits, protection failures, abnormal log or report data, access timeouts, or redirection to DDoS scrubbing or blackhole filtering.
- To remove an instance from the sandbox, upgrade its QPS specification. For more information, see Sandbox overview.

Enable burstable QPS

Go to the Web Application Firewall 3.0 buy page.

Set billing method to subscription, and then set a value for Burst QPS (Pay-As-You-Go).

The maximum specification for Burst QPS (Pay-As-You-Go) varies by edition.

Edition	Chinese mainland	Outside the Chinese mainland
Basic Edition	Does not support Burst QPS (Pay-As-You-Go)	Burst QPS (Pay-As-You-Go) is not supported.
Pro Edition	Up to 60,000 QPS	Up to 1,000 QPS
Enterprise Edition	Up to 60,000 QPS. If your business requirements exceed this limit, contact your account manager or architect.	Up to 1,000 QPS. If your business requirements exceed this limit, contact your account manager or architect.
Ultimate Edition

Note

Setting Burst QPS (Pay-As-You-Go) to 0 QPS disables the burstable QPS feature.

After confirming the configuration, click Purchase Now and complete the payment.

Bill management

Log on to the Web Application Firewall 3.0 console. From the top menu bar, select the resource group and region (Chinese Mainland or Outside Chinese Mainland) for the WAF instance.
In the left-side navigation pane, choose Bill Management.
In the bill list, you can view daily details for your instance, including the burstable billing type, burstable billing unit price, peak QPS, current QPS specification, total fee, and instance status.