自适应限流功能探讨

**1、实际业务应用中该功能使用的多吗？效果如何？
2、当前自适应限流功能只支持method级别，能否支持全局级别？
3、既然是自适应的策略能否默认开启？如不能是有什么原因吗？
盼回复**

Start by reviewing the existing method-level adaptive rate-limiting implementation and its configuration or usage guidance. Determine whether global-level support and enabling the strategy by default are technically and operationally appropriate. Done would require a decided scope and documented answers to the three questions, rather than an implementation based on the current discussion alone.

Written by the indexing model from the issue text.