Pay-per-Use Billing

Pay-per-use billing is a postpaid mode in which you pay for what you use. This billing mode requires no upfront or long-term commitments. This topic describes the billing rules of pay-per-use WAF resources.

Application Scenario

Pay-per-use billing is suitable for applications or services that cannot be interrupted but have unpredictable or sudden traffic surges, such as flash sale activities on e-commerce platforms, temporary testing, and scientific computing.

Billing Items

Cloud mode: the number of domain names, the number of custom rules, and the number of requests
Dedicated mode: the number of instances

Billing Period

Pay-per-use WAF resources are billed by second. Bills are settled on each integer hour (UTC+08:00). After the settlement is complete, a new billing period starts.

For a pay-per-use cloud WAF instance, you are billed for the number of added domain names, number of customized rules, and number of forwarded requests.
For a pay-per-use dedicated WAF instance, you are billed for the required duration (accurate to second), which starts when the instance is created and ends when the instance is deleted.

For example, if you purchased a dedicated WAF instance at 8:45:30 on June 8, 2023 and then deleted it at 8:55:00 on that day, the billing cycle is from 8:00:00 to 9:00:00, and the billing duration is calculated from 8:45:30 to 8:55:30, which is 600 seconds.

Billing Examples

If you purchased a pay-per-use cloud WAF instance at 08:00:00 on June 8, 2023 and disabled the pay-per-use billing mode at 18:00:00 on that day, the billing duration is 10 hours. During the billing cycle, two domain names and two rules were added, and 10 million requests were forwarded by WAF.

Figure 1 Example of pay-per-use billing in cloud mode

If you purchased two pay-per-use dedicated WAF instance at 08:00:00 on June 8, 2023 and deleted them at 18:00:00 on that day, the billing duration is 10 hours. The billing details are as follows:

Number of WAF instances: 2
WAF instance specifications: WI-100

Figure 2 Pay-per-use billing for dedicated WAF instances

Impacts of Arrears

Figure 3 describes the status of pay-per-use WAF resources in different periods. After you purchase WAF resources, the phase during which the resources run properly within the billing cycle is the validity period. If your account is in arrears due to failed payment for the pay-per-use WAF resources, the resources enter the grace period and then retention period.

Figure 3 Resource Lifecycle

Arrears notifications

The system deducts fees from your account balance for pay-per-use resources at the end of each billing cycle. If your account goes into arrears, we will notify you by email, SMS, or internal message.

Arrears impacts

If you purchase pay-per-use dedicated WAF instances or cloud WAF, fees are deducted from your account balance. Your account may fall into arrears if the balance cannot cover the fees. If your account gets into arrears, WAF enters the grace period and still protects your website during this period. You need to pay the pay-per-use resource fees incurred during the grace period. To view the fees, go to the Billing Center > Overview page. The system will charge the fees once you top up your account.

If you do not pay the overdue fees within the grace period, the resource enters the retention period and the resource status changes to Frozen. In the retention period, you cannot perform any operation on the pay-per-use resources, and WAF only forwards website requests without examining any traffic.

If the fees still fail to be paid when the retention period ends, domain name configurations in WAF will be deleted. During the clearing period, domain names are pointed back to origin severs by default. However, services on your domain names may not run properly because there may be inconsistencies between your configured protocols and ports.