微服务架构之spring cloud hystrix&hystr

作者: 架构师联盟 | 来源:发表于2020-05-12 10:14 被阅读0次

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();
}

i. FeignClient feign客户端配置，这里配置了服务名称、重试规则、失败回调，fallback 属性就是熔断器提供的功能，这点在后面的熔断器看板中可以更直观的看到。