第一步：添加依赖
https://blog.csdn.net/goldenfish1919/article/details/108192745从

从版本3.0.1 release开时，Hystrix 从spring Cloud Netflix 移除。 

1:    circuitbreaker  断路器; 熔断机制; 断路开关;   

       circuit [?s??k?t]  环行; 环行路线; 电路; 线路; 巡回赛;     

2:     resilience4j  [r??z?li?ns]  可以实现熔断机制之，可以使用reactive 反应式编程。也可以使用非反应式编程。

• org.springframework.cloud:spring-cloud-starter-circuitbreaker-resilience4j - non-reactive applications

• org.springframework.cloud:spring-cloud-starter-circuitbreaker-reactor-resilience4j - reactive applications

3： 与spring gateway 集成

spring:
  cloud:
    gateway:
      httpclient:
        connect-timeout: 5000
        response-timeout: 5s
        ssl:
          close-notify-flush-timeout-millis: 3000
          close-notify-read-timeout-millis: 0
          handshake-timeout-millis: 10000
          useInsecureTrustManager: true
      routes:
        # mms
        # dseCallback
        - id: dseCallback_route
          predicates:
            - Path=/one/**
          uri: https://httpbin.org/
          filters:
            - args:
               name: myCircuitBreaker
               fallbackUri: http://127.0.0.1/get
              name: CircuitBreaker
            - StripPrefix=1

可以看出，在延迟情况下，会使用fallbackUri中的路径。

curl http://127.0.0.1:8080/one/delay/1
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 507 100 507 0 0 97 0 0:00:05 0:00:05 --:--:-- 127{
"args": {},
"data": "",
"files": {},
"form": {},
"headers": {
"Accept": "*/*",
"Content-Length": "0",
"Forwarded": "proto=http;host=\"127.0.0.1:8080\";for=\"127.0.0.1:64562\"",
"Host": "httpbin.org",
"User-Agent": "curl/7.77.0",
"X-Amzn-Trace-Id": "Root=1-612337f6-21e016c8485d317635383176",
"X-Forwarded-Host": "127.0.0.1:8080",
"X-Forwarded-Prefix": "/one"
},
"origin": "127.0.0.1, 183.230.102.102",
"url": "https://127.0.0.1:8080/delay/1"
}

liujianping@DESKTOP-JR50M1H MINGW32 /d/lianxi
$ curl http://127.0.0.1:8080/one/delay/1000
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 238 100 238 0 0 38 0 0:00:06 0:00:06 --:--:-- 59{"args":{},"headers":{"Accept":"*/*","Accept-Encoding":"gzip","Host":"httpbin.org","User-Agent":"ReactorNetty/1.0.9","X-Amzn-Trace-Id":"Root=1-6123383d-6811ed7c2132cc3e01d62f7f"},"origin":"183.230.102.102","url":"https://httpbin.org/get"}

1： 自定义配置，超时设置，这里定义的是请求超时，一但超时，进入降级模式。默认为1

@Bean
public Customizer<ReactiveResilience4JCircuitBreakerFactory> defaultCustomizer() {
   return factory -> factory.configureDefault(id -> new Resilience4JConfigBuilder(id)
         .circuitBreakerConfig(CircuitBreakerConfig.ofDefaults())
         .timeLimiterConfig(TimeLimiterConfig.custom().timeoutDuration(Duration.ofSeconds(2)).build()).build());
}

GateWay与熔断器