Billing of intelligent load balancing and how to use intelligent load balancing - Web Application Firewall

Web Application Firewall (WAF) supports intelligent load balancing. WAF uses the intelligent multi-node access technology to ensure that access requests to websites are automatically scheduled among multiple nodes or lines to achieve disaster recovery. This ensures high service availability and reduces access latency.

Scenarios

Intelligent load balancing helps ensure availability and reduce access latency and is suitable for the following services:

Active geo-redundancy services: Multiple nodes are deployed on the cloud or in data centers across regions. The nodes simultaneously provide services and work as backups for each other to achieve disaster recovery. Active geo-redundancy services require high reliability, and access latency needs to be minimized for the services.
Co-location multi-active services: Multiple nodes are deployed on the cloud or in data centers in the same region. The nodes simultaneously provide services and work as backups for each other to achieve disaster recovery. Co-location multi-active services require high reliability.
Co-location single-active services: A single node is deployed on the cloud or in a data center in the same region to provide services. Co-location single-active services require high reliability.
Note
Co-location single-active services do not provide automatic disaster recovery capabilities. You can enable intelligent load balancing to ensure the reliability of the services.

How it works

After you enable intelligent load balancing for a WAF instance, the WAF instance is allocated at least three protection nodes that reside in different regions to achieve automatic disaster recovery. The WAF instance uses the intelligent DNS resolution feature and the least-time back-to-origin algorithm to reduce the latency of traffic from protection nodes to origin servers.

Note

After you enable intelligent load balancing for a WAF instance in the Chinese mainland, the WAF instance is allocated one node in each of the following regions: China (Beijing), China (Hangzhou), and China (Shenzhen).
After you enable intelligent load balancing for a WAF instance outside the Chinese mainland, the WAF instance is allocated one node in each of the following areas: North America, Europe, and Southeast Asia.

The following table describes the capabilities of a WAF instance before and after intelligent load balancing is enabled.

Capability	Before	After
Disaster recovery	Access protection based on multiple single-active nodes Standard failover for disaster recovery	Access protection based on multi-node load balancing Automatic failover based on intelligent DNS resolution
Access acceleration	N/A	Shortest link based on the closest protection node and origin server

Benefits

The following table describes the benefits of intelligent load balancing.

Scenario	Benefit	Architecture
Active geo-redundancy services	Automatic disaster recovery on multiple lines to achieve automatic recovery from faults Distributed health check to balance loads on multiple lines Upgraded least-time back-to-origin algorithm to reduce latency
Co-location multi-active services	Automatic disaster recovery on multiple lines to achieve automatic recovery from faults Distributed health check to balance loads on multiple lines
Co-location single-active services	Automatic disaster recovery on multiple lines to achieve automatic recovery from faults Distributed health check to balance loads on multiple lines

Billing

By default, the intelligent load balancing feature is disabled. You must purchase the feature before you can use the feature.

When you use intelligent load balancing, you are charged based on the subscription period of the WAF instance. The following list describes the billing rules.

WAF instances in the Chinese mainland: USD 180/month
WAF instances outside the Chinese mainland: USD 800/month

Use intelligent load balancing

To use intelligent load balancing, perform the following steps:

Enable intelligent load balancing for your WAF instance.
You can enable intelligent load balancing when you purchase a WAF instance. You can also enable intelligent load balancing when you upgrade a WAF instance. For more information, see Renewal and upgrade of a subscription WAF instance.
Important
Only the WAF Business and Enterprise editions support intelligent load balancing in regions outside the Chinese mainland.
Add your website to WAF in CNAME record mode. In the Enter Your Website Information step, enter the addresses of all origin servers in the Origin Server Address section and select Least time for the Load Balancing Algorithm parameter. Configure other website information based on your business requirements. For more information, see Add a domain name to WAF.
Update the DNS record of your website to map the domain name to the CNAME that is provided by WAF. This way, requests that are destined for your website are protected by WAF. For more information, see Modify a DNS record.

After you add your website to WAF, WAF uses the intelligent DNS resolution feature and the least-time back-to-origin algorithm to reduce the latency of traffic from protection nodes to origin servers.

Important

If you use an A record to map the domain name that you added to WAF to the virtual IP address (VIP) of WAF, your web services may be inaccessible after you enable or disable intelligent load balancing.