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

Scenarios

Intelligent load balancing helps achieve high availability and minimize 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. These nodes simultaneously provide services and work as backups for each other to achieve disaster recovery. Active geo-redundancy services require high reliability and low access latency.
  • Co-location multi-active services: Multiple nodes are deployed on the cloud or in data centers in the same region. These nodes simultaneously provide services and work as backups for each other to achieve disaster recovery. Co-location multi-active services require high reliability and low access latency.
  • 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.
    Note Co-location single-active services do not have automatic disaster recovery capabilities. You can enable intelligent load balancing to achieve high service availability, automatic disaster recovery, and minimum access latency for these services.

How intelligent load balancing works

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

Note
  • After you enable intelligent load balancing for a WAF instance in mainland China, 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 mainland China, the WAF instance is allocated one node in each of the following regions: India (Mumbai), China (Hong Kong), Germany (Frankfurt), UAE (Dubai), and Singapore (Singapore).
How intelligent load balancing works

The following table describes the capabilities of your WAF instance after you enable intelligent load balancing.

Capability Before intelligent load balancing is enabled After intelligent load balancing is enabled
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 The shortest link due to 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 among multiple lines to achieve automatic recovery from faults
  • Distributed health check to balance loads among multiple lines
  • Upgraded least-time back-to-origin algorithm to minimize latency
Benefits to active geo-redundancy services
Co-location multi-active services
  • Automatic disaster recovery among multiple lines to achieve automatic recovery from faults
  • Distributed health check to balance loads among multiple lines
Benefits to co-location multi-active services
Co-location single-active service
  • Automatic disaster recovery among multiple lines to achieve automatic recovery from faults
  • Distributed health check to balance loads among multiple lines
Benefits to co-location single-active services

Billing

The subscription fee for your WAF instance does not cover the intelligent load balancing feature. The intelligent load balancing feature is separately charged.

When you use intelligent load balancing, you are charged on a monthly basis during the service period of your WAF instance.

  • WAF instances in mainland China: USD 180/month
  • WAF instances outside mainland China: USD 800/month

Use intelligent load balancing

To use intelligent load balancing, perform the following steps:

  1. Enable intelligent load balancing for your WAF instance.
    To enable intelligent load balancing, set the Intelligent Load Balancing parameter to Yes when you purchase a subscription WAF instance. You can also set the Intelligent Load Balancing parameter to Yes when you upgrade a subscription WAF instance. For more information, see Purchase a WAF instance and Renewal and upgrade.
    Notice In regions outside mainland China, only the WAF Pro and Enterprise editions support intelligent load balancing.
  2. Add your website to WAF in CNAME record mode. In the Enter Your Website Information step, enter the addresses of all origin servers in Destination Server (IP Address) and select Least time for Load Balancing Algorithm. Configure other website information based on your business requirements. For more information, see Manually add website configurations. Load Balancing Algorithm
  3. Change the DNS record of your website to resolve 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 Change a DNS record.

After your website is added to WAF, WAF automatically uses the intelligent DNS resolution feature and least-time algorithm to minimize the latency of traffic from protection nodes to origin servers.