Web Application Firewall (WAF) provides intelligent load balancing. By leveraging the intelligent multi-node access technology, WAF ensures 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.

Note Only subscription WAF instances support intelligent load balancing. Instances deployed in mainland China must be of the Pro edition or higher. Instances deployed outside mainland China must be of the Business edition or higher.
Intelligent load balancing is best suited to the following services to achieve high availability and minimize access latency:
  • 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.
  • 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 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. However, you can enable intelligent load balancing to achieve high service availability and automatic disaster recovery, and minimize access latency.

How intelligent load balancing works

After intelligent load balancing is enabled, a WAF instance is allocated a minimum of three protection nodes that are deployed in different regions to achieve automatic disaster recovery. In addition, the intelligent DNS resolution feature and the upgraded least-time back-to-origin algorithm are used to minimize the latency when traffic is forwarded to origin servers.

Note
  • After intelligent load balancing is enabled for a WAF instance in mainland China, the WAF instance is allocated three protection nodes, with one node deployed in the China (Beijing) region, one in the China (Hangzhou) region, and one in the China (Shenzhen) region.
  • After intelligent load balancing is enabled for a WAF instance outside mainland China, the WAF instance is allocated the protection nodes that are deployed in different regions, with one node in each region. The regions include India (Mumbai), China (Hong Kong), Germany (Frankfurt), UAE (Dubai), and Singapore (Singapore).
How intelligent load balancing works

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

Capability Before this feature is enabled After this feature is enabled
Disaster recovery
  • Access protection based on multiple single-active nodes
  • Unified 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

Intelligent load balancing brings you the following benefits:

  • Active geo-redundancy services
    • Automatic disaster recovery among multiple lines to achieve fault recovery
    • 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 fault recovery
    • 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 fault recovery
    • Distributed health check to balance loads among multiple lines
    Benefits to co-location single-active services

Enable intelligent load balancing

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.

Intelligent load balancing is 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