Forwarding Policy Priorities of LoadBalancer Ingresses

Default Sorting

If the ELB advanced forwarding policies are not enabled, the default sorting rule of forwarding policies is as follows:

• Forwarding rule priorities are independent of each other regardless of domain names. When a request matches both a domain name-based rule and a URL-based rule, the domain name-based rule is matched first.
• URL-based forwarding rules are applied in the following order of priority: an exact match rule, a prefix match rule, and a regular expression match rule. For multiple matches of the same type, only the longest URL-based forwarding rule will be applied.

Once a forwarding policy is created, the system automatically sorts it based on the default sorting rule. Examples are as follows:

• The access request to www.example.com/test1/test2 matches both forwarding policies 2 and 3. If the match types are the same, the priority is determined by the length of the URL, with longer URLs having higher priority. In this case, the access request will be forwarded based on the forwarding policy 2.
• The access request to www.example.com/test1/test2/test3 matches forwarding policies 1, 2, and 3. An exact match is preferred, so the access request will be forwarded based on the forwarding policy 1.

Priority

With ELB advanced forwarding policies enabled, each request is matched based on the forwarding policy priority (a smaller value indicates a higher priority). Once a forwarding policy is matched, the request is forwarded based on this forwarding policy.

The rules for configuring the priority of a forwarding policy are as follows:

• The existing forwarding policies will maintain their original priority sequence before an advanced forwarding policy is configured.
• Once an advanced forwarding policy is set up, any new forwarding policy added will have the lowest priority. The default forwarding policy always has the lowest priority and is not included in the sorting process. Additionally, you have the option to manually specify the priority of a new forwarding policy. For details, see Configuring the Priorities of Forwarding Rules for LoadBalancer Ingresses.

In this example, the access request to www.example.com/test1 satisfies both forwarding policies 1 and 2, so the request will be forwarded based on the forwarding policy 1.