You can configure rules to specify whether the configurations of Edge Security Acceleration (ESA) take effect for specific requests based on the characteristics of the requests. This helps meet your business requirements such as applying specific settings to requests with different characteristics, redirecting requests, and configuring specific origin servers.
Feature description
The rules engine of Alibaba Cloud DCDN allows you to use the same basic syntax and configuration logic to filter requests with specific characteristics and and apply custom settings such as cache, redirect, compression, origin, and Web Application Firewall (WAF) settings to these requests.
The rules engine supports the filtering of requests with different characteristics. For more information, see Filterable request characteristics supported by the rules engine.
Priority of rules
If you configure a feature, such as the browser cache time-to-live (TTL) feature, in global settings and rule configurations at the same time, the rule configurations prevail.
If you specify multiple rules, such as cache rules, the rules are executed from top to bottom in the configuration list. You can change the position of the rules in the list to change their execution order.
Usage notes
Different plans support different features and rules. DCDN allows you to configure specific features only after you upgrade your plans to the specified plans.
Filterable request characteristics
A complete rule that is used to filter requests consists of conditional expressions and logical operators. You can specify multiple conditional expressions and combine them to filter requests. For more information, see Rules engine.