微服务架构之spring cloud hystrix&hystrix dashboard

在前面介绍spring cloud feign中我们已经使用过hystrix，只是没有介绍，spring cloud hystrix在spring cloud中起到保护微服务的作用，不会让发生的异常无边界的蔓延下去，很像我们电路中的保险设置，有超压或者线路有问题就即时的断开，保护用电设备不被损坏，这篇文章就来介绍spring cloud hystrix及其hystrix dashboard。

(一) 版本说明

a) Spring boot 2.0.6.RELEASE

b) Spring cloud Finchley.SR2

c) Java version 1.8

d) spring-cloud-starter-netflix-hystrix 2.0.2.RELEASE

e) spring-cloud-starter-netflix-hystrix-dashboard 2.0.2.RELEASE

(二) 项目配置

1. 项目设置

a) POM设置

<dependency>

<groupId>org.springframework.cloud</groupId>

<artifactId>spring-cloud-starter-netflix-hystrix</artifactId>

</dependency>

<dependency>

<groupId>org.springframework.cloud</groupId>

<artifactId>spring-cloud-starter-netflix-hystrix-dashboard</artifactId>

</dependency>

b) application.yml配置文件

eureka:

datacenter: ctm

environment: dev

instance:

hostname: 192.168.1.78

prefer-ip-address: true

ip-address: 192.168.1.129

lease-renewal-interval-in-seconds: 10

lease-expiration-duration-in-seconds: 30

instance-id: ${eureka.instance.ip-address}:${server.port}

client:

service-url:

defaultZone: http://${eureka.instance.hostname}:1001/eureka/,http://${eureka.instance.hostname}:1002/eureka/,http://${eureka.instance.hostname}:1003/eureka/

fetch-registry: true

register-with-eureka: true

healthcheck:

enabled: true

feign:

hystrix:

enabled: true

c) 主要参数说明

i. eureka.instance.prefer-ip-address 使用IP显示注册信息

ii. eureka.instance.ip-address 实例IP地址，

iii. eureka.instance.instance-id 自定义实例id，服务之间调用就是使用该配置，多个实例必须保证唯一性

iv. eureka.client.service-url.defaultZone 注册中心地址

v. feign.Hystrix.enabled 在feign中其中熔断器

d) 服务提供者API

@Value("${server.port}")

private String getPort;

@GetMapping(name = "index", value = "/index")

public String Index() {

return getPort;

}

2. feign消费端项目配置

a) POM设置

<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-feign</artifactId>

</dependency>

i. 这里把服务消费端也注册到了服务治理中心，消费者同时也是其它服务的提供者。

b) application.yml配置文件

eureka:

datacenter: ctm

environment: dev

instance:

hostname: 192.168.1.78

prefer-ip-address: true

ip-address: 192.168.1.129

lease-renewal-interval-in-seconds: 10

lease-expiration-duration-in-seconds: 30

instance-id: ${eureka.instance.ip-address}:${server.port}

client:

service-url:

defaultZone: http://${eureka.instance.hostname}:1001/eureka/,http://${eureka.instance.hostname}:1002/eureka/,http://${eureka.instance.hostname}:1003/eureka/

fetch-registry: true

register-with-eureka: true

healthcheck:

enabled: true

c) feign服务消费者API

@Configuration

public class FeignConfig {

@Bean

public Retryer feignRetryer(){

return new Retryer.Default(100, TimeUnit.SECONDS.toMillis(1),3);

}

}

@Component

public class FallBackService implements FeignService {

@Override

public String Index() {

return "hi,feign,error!";

}

}

@Component

@FeignClient(name = "DEMOSERVICEIMPL",configuration = FeignConfig.class,fallback = FallBackService.class)

public interface FeignService {

@GetMapping(value = "/index")

String Index();

}