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

What is intelligent load balancing?

After you enable intelligent load balancing for a WAF instance, the WAF instance is allocated at least three protection nodes in different regions to implement automatic disaster recovery across nodes and regions. WAF uses the intelligent DNS resolution feature and the least response time algorithm to minimize the path and latency when requests are forwarded to origin servers.

Intelligent load balancing applies only to the service that is added to WAF in CNAME record mode. By default, intelligent load balancing is disabled for a WAF instance. The following table describes the capabilities of your WAF instance that has intelligent load balancing enabled.
Capability Before intelligent load balancing is enabled After intelligent load balancing is enabled
Disaster recovery
  • Protection capabilities based on multiple single-active nodes for the services that are added to WAF
  • Standard failover for disaster recovery
  • Protection capabilities based on multi-node load balancing for the services that are added to WAF
  • Automatic failover based on intelligent DNS resolution in case of network failures
Access acceleration N/A Protection capabilities based on the nearest protection node, and the shortest path to the nearest origin server
Intelligent load balancing

Benefits

The following table describes the benefits of intelligent load balancing.
Scenario Business characteristic Benefit Architecture
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.

  • Automatic disaster recovery among multiple lines to achieve automatic recovery from network failures
  • Distributed health check to balance loads among multiple lines
  • Upgraded least response time algorithm to minimize latency
Benefits to active geo-redundancy services
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.
  • Automatic disaster recovery among multiple lines to achieve automatic recovery from network failures
  • Distributed health check to balance loads among multiple lines
Co-location multi-active services
Co-location single-active service A single node is deployed on the cloud or in a data center in the same region to provide online 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.
  • Automatic disaster recovery among multiple lines to achieve automatic recovery from network failures
  • Distributed health check to balance loads among multiple lines
Co-location single-active service

Billing

You are charged for the intelligent load balancing feature. The fees are billed to the WAF instance for which you enable the feature.

After you enable intelligent load balancing for one or multiple domain names that are added to a WAF instance in CNAME record mode, intelligent load balancing is enabled for the WAF instance. You are charged regardless of the number of domain names. For more information, see Billing method.

Enable intelligent load balancing

You can enable intelligent load balancing only for domain names that are added to WAF in CNAME record mode.

To enable intelligent load balancing, perform the following steps:
  1. On the Website Configuration page of the WAF 3.0 console, click Add on the CNAME Record tab. The Add Domain Name wizard appears.
  2. In the Configure Listener step, click More Settings, and set Protection Resource to Shared Cluster-based Intelligent Load Balancing. Load balancing algorithm
  3. In the Change Forwarding Rule step, set Load Balancing Algorithm to Least time. Laod balancing algorithm
For more information, see Configuration wizard description.

After your complete the preceding configurations, WAF automatically uses the intelligent DNS resolution feature and least response time algorithm to minimize the path and latency of traffic from protection nodes to origin servers.