Support default rules | 如果有几百个接口，每一个接口的限流和降级规则都需要在客户端配置吗，有没有一个默认全局的

如果有几百个接口，每一个接口的限流和降级规则都需要在客户端配置吗，有没有一个默认全局的配置，比如像Hystrix一样异常比例达到某个阈值就能自动降级一段时间

Start by reviewing Sentinel’s existing client-side flow-control and degradation rule configuration, then compare it with the Hystrix-style exception-ratio behavior requested here. The issue mentions no files or tests; done would require an agreed design for global defaults, automatic degradation thresholds, and the duration of that degradation.

Written by the indexing model from the issue text.