Web Application Firewall (WAF) provides intelligent load balancing. With the multi-node intelligent access technology, WAF ensures that access to your business application is automatically scheduled among multiple nodes or lines to achieve disaster recovery. This ensures high service availability and low-latency access.

Note Only WAF subscription instances support intelligent load balancing. This feature is available in WAF Pro, Business, and Enterprise Editions in mainland China and in WAF Business and Enterprise Editions outside China.

WAF Exclusive Edition does not support intelligent load balancing.

Intelligent load balancing is best suited to the following services to achieve high availability and low-latency access:
  • Active geo-redundancy services: Multiple nodes are deployed on the cloud or in Internet data centers (IDCs) deployed across multiple regions. These nodes provide services simultaneously 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 IDCs deployed in the same region. These nodes provide services simultaneously 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 an IDC to provide services.
    Note Co-location single-active services do not have automatic disaster recovery capabilities. However, you can activate intelligent load balancing to achieve highly reliable, automatic disaster recovery and low-latency, accelerated access.

Feature principles

After intelligent load balancing is activated, a WAF instance has at least three protection nodes that are deployed in different regions to achieve automatic disaster recovery. In addition, the intelligent DNS resolution feature and the least-time back-to-origin algorithm are used to shorten the delay from the moment the traffic accesses a protection node to the moment the traffic is forwarded to the origin server.

Note
  • After intelligent load balancing is activated in mainland China, a WAF instance has 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 activated outside China, a WAF instance has eight protection nodes that are deployed in different regions, including India (Mumbai), China (Hong Kong), Germany (Frankfurt), UAE (Dubai), and Singapore.
Principles of intelligent load balancing

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

Capability Before this feature is activated After this feature is activated
Disaster recovery
  • Access protection based on multiple nodes with one active
  • Unified 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 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 ensure low 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

Activate intelligent load balancing

When you purchase a WAF subscription instance, you can enable the basic configuration item intelligent load balancing. You can also enable this basic configuration item when you upgrade the configurations of a WAF subscription 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 China: USD 800/month