1.GitHub地址
https://github.com/Netflix/Hystrix
https://github.com/Netflix/Hystrix/wiki
官方文档
2.为什么要用Hystrix?
在一个分布式系统里，一个服务依赖多个服务，可能存在某个服务调用失败，
比如超时，异常等，如何能保证在一个依赖出问题的情况下，不会导致整体服务失败，
通过Hystrix就可以解决
3.功能
提供熔断，隔离，Fallback，cache，监控等功能
4.熔断后怎么处理？
出现错误后，可以Fallback错误的处理信息
5.代码实现
1）添加依赖
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-openfeign</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-netflix-hystrix</artifactId> </dependency>
2）启动类添加@EnableCircuitBreaker
import org.mybatis.spring.annotation.MapperScan; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.cloud.client.circuitbreaker.EnableCircuitBreaker; import org.springframework.cloud.openfeign.EnableFeignClients; @SpringBootApplication @MapperScan("cn.ytheng.order_service") @EnableFeignClients @EnableCircuitBreaker public class OrderServiceApplication { public static void main(String[] args) { SpringApplication.run(OrderServiceApplication.class, args); } }
3）添加feign，为了测试Product服务挂掉的情况
import org.springframework.cloud.openfeign.FeignClient; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestParam; /** * * 商品服务客户端 * product-service: 调用服务名称，即spring.application.name * */ @FeignClient(name = "product-service") public interface ProductClient { @GetMapping("/api/v1/product/find") String getById(@RequestParam("id") int id); }
4）添加controller
package cn.theng.order_service.controller; import cn.theng.order_service.service.ProductClient; import com.netflix.hystrix.contrib.javanica.annotation.HystrixCommand; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.PostMapping; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.bind.annotation.RestController; import java.util.HashMap; import java.util.Map; @RestController @RequestMapping("/api/v1/order") public class ProductOrderController { @Autowired private ProductClient productClient; @PostMapping("/test2") @HystrixCommand(fallbackMethod = "getProductFail") public Object test2(@RequestParam("product_id") int productId) { //如果把Product服务关掉，这里就会报错，然后调下面的方法 String product = productClient.getById(productId); return "success"; } //方法签名一定要与上面方法保持一致 public Object getProductFail(int productId) { Map<String, Object> map = new HashMap<>(); map.put("code", -1); map.put("msg", "目前排队人数过多，请稍后再试..."); return map; } }
5）修改application.yml配置
server: port: 8781 eureka: client: serviceUrl: defaultZone: http://localhost:8761/eureka/ spring: application: name: order-service #设置调用服务超时时间 #product-service为服务名称，也可以设置为默认值default feign: client: config: product-service: connectTimeout: 5000 readTimeout: 11000
6.访问地址
SpringCloud------熔断器Hystrix的使用
原文：https://www.cnblogs.com/tianhengblogs/p/12487495.html