Hystrix快速入门

1、引入Maven依赖

<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-hystrix</artifactId>
</dependency>

 

2、启动类使用@EnableCircuitBreaker注解

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.circuitbreaker.EnableCircuitBreaker;
@SpringBootApplication
@EnableCircuitBreaker
public class HystrixApplication {
public static void main(String[] args) {
SpringApplication.run(HystrixApplication.class, args);
}
}

 

3、使用@HystrixCommand注解，并配置fallbackMethod
@HystrixCommand由名为“javanica”的Netflix contrib库提供。Spring Cloud在连接到Hystrix断路器的代理中使用该注解自动包装Spring bean。断路器计算何时打开和关闭电路，以及在发生故障时应该做什么。

package com.mimaxueyuan.consumer.turbine.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import com.mimaxueyuan.consumer.turbine.service.MyService;
import com.netflix.hystrix.contrib.javanica.annotation.HystrixCommand;
@RestController
public class HelloController {
@Autowired
private MyService myService;
/**
* 模拟id为"ok"时请求成功，其它值让请求休眠5秒超时
*
* @param id
* @return
* @author lynch
*/
@GetMapping("/hello/{id}")
@HystrixCommand(fallbackMethod = "getError")
public String hello(@PathVariable String id) {
if(!"ok".equals(id)) {
try {
System.out.println(Thread.currentThread().getName()+":hello before sleep 5s....");
Thread.sleep(1000 * 5);
System.out.println(Thread.currentThread().getName()+":hello after sleep 5s....");
} catch (InterruptedException e) {
e.printStackTrace();
}
}
return "请求成功，id=" + id;
}
public String getError(String id) {
System.out.println(Thread.currentThread().getName()+":getError before ....");
//myService.execute();
System.out.println("断路器已触发，并作相应的业务处理...");
System.out.println(Thread.currentThread().getName()+":getError after ....");
return "请求超时，使用断路器返回，id=" + id;
}
}

 

4、模拟url请求
4.1、正常请求

4.2、超时请求，使用断路器返回

4.3控制台输出信息

hystrix-HelloController-2:hello before sleep 5s....
HystrixTimer-1:getError before ....
断路器已触发，并作相应的业务处理...
HystrixTimer-1:getError after ....
java.lang.InterruptedException: sleep interrupted
at java.lang.Thread.sleep(Native Method)
at com.mimaxueyuan.consumer.turbine.controller.HelloController.hello(HelloController.java:30)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.netflix.hystrix.contrib.javanica.command.MethodExecutionAction.execute(MethodExecutionAction.java:116)
at com.netflix.hystrix.contrib.javanica.command.MethodExecutionAction.executeWithArgs(MethodExecutionAction.java:93)
at com.netflix.hystrix.contrib.javanica.command.MethodExecutionAction.execute(MethodExecutionAction.java:78)
at com.netflix.hystrix.contrib.javanica.command.GenericCommand$1.execute(GenericCommand.java:48)
at com.netflix.hystrix.contrib.javanica.command.AbstractHystrixCommand.process(AbstractHystrixCommand.java:145)
at com.netflix.hystrix.contrib.javanica.command.GenericCommand.run(GenericCommand.java:45)
at com.netflix.hystrix.HystrixCommand$2.call(HystrixCommand.java:302)
at com.netflix.hystrix.HystrixCommand$2.call(HystrixCommand.java:298)
at rx.internal.operators.OnSubscribeDefer.call(OnSubscribeDefer.java:46)
at rx.internal.operators.OnSubscribeDefer.call(OnSubscribeDefer.java:35)
at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:48)
at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:30)
at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:48)
at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:30)
at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:48)
at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:30)
at rx.Observable.unsafeSubscribe(Observable.java:10151)
at rx.internal.operators.OnSubscribeDefer.call(OnSubscribeDefer.java:51)
at rx.internal.operators.OnSubscribeDefer.call(OnSubscribeDefer.java:35)
at rx.Observable.unsafeSubscribe(Observable.java:10151)
at rx.internal.operators.OnSubscribeDoOnEach.call(OnSubscribeDoOnEach.java:41)
at rx.internal.operators.OnSubscribeDoOnEach.call(OnSubscribeDoOnEach.java:30)
at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:48)
at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:30)
at rx.Observable.unsafeSubscribe(Observable.java:10151)
at rx.internal.operators.OperatorSubscribeOn$1.call(OperatorSubscribeOn.java:94)
at com.netflix.hystrix.strategy.concurrency.HystrixContexSchedulerAction$1.call(HystrixContexSchedulerAction.java:56)
at com.netflix.hystrix.strategy.concurrency.HystrixContexSchedulerAction$1.call(HystrixContexSchedulerAction.java:47)
at com.netflix.hystrix.strategy.concurrency.HystrixContexSchedulerAction.call(HystrixContexSchedulerAction.java:69)
at rx.internal.schedulers.ScheduledAction.run(ScheduledAction.java:55)
at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)