SpringCloud Bus消息总线

SpringCloud Bus 消息总线

上一讲解的加深和扩充，一言以蔽之

• 分布式自动刷新配置功能

• Spring Cloud Bus配合Spring Cloud Config使用可以实现配置的动态刷新

是什么？

Bus支持两种消息代理：RabbitMQ和Kafka

能干嘛？

为何被称为总线

RabbitMQ环境配置

安装Erlang，下载地址：http://erlang.org/download/otp_win64_21.3.exe

安装RabbitMQ，下载地址

https://dl.bintray.com/rabbitmq/all/rabbitmq-server/3.7.14/rabbitmq-server-3.7.14.exe

进入RabbitMQ安装目录下的sbin目录

如例我自己本机D:\scmq\rabbitmq_server-3.7.14\sbin

输入以下命令启动管理功能

rabbitmq-plugins enable rabbitmq_management

可视化插件

访问地址查看是否安装成功

http://localhost:15672/

输入账号密码并登录: guest guest

SpringCloud Bus动态刷新全局广播

必须先具备良好的RabbitMQ环境先

演示广播效果，增加复杂度，再以3355为模板再制作一个3366

新建cloud-config-client-3366

pom

<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-config</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
    </dependency>
    <dependency>
        <groupId>com.kayleh.springcloud</groupId>
        <artifactId>cloud-api-commons</artifactId>
        <version>${project.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-actuator</artifactId>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <scope>runtime</scope>
        <optional>true</optional>
    </dependency>

    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <optional>true</optional>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
</dependencies>

bootstrap.yml

server:
  port: 3366

spring:
  application:
    name: config-client
  cloud:
    config:
      label: master
      name: config
      profile: dev
      uri: http://localhost:3344
eureka:
  client:
    service-url:
      defaultZone: http://eureka7001.com:7001/eureka
management:
  endpoints:
    web:
      exposure:
        include: "*"

主启动类

package com.kayleh.springcloud;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;

@EnableEurekaClient
@SpringBootApplication
public class ConfigClientMain3366 {
    public static void main(String[] args) {
            SpringApplication.run( ConfigClientMain3366.class,args);
        }
}
 

controller

package com.kayleh.springcloud.controller;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.cloud.context.config.annotation.RefreshScope;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RefreshScope
public class ConfigClientController {

    @Value("${server.port}")
    private String serverPort;

    @Value("${config.info}")
    private String configInfo;


    @GetMapping("/configInfo")
    public String getConfigInfo(){
        return "serverPort:"+serverPort+"\t\n\n configInfo: "+configInfo;
    }
}

设计思想

1. 利用消息总线触发一个客户端/bus/refresh,而刷新所有客户端的配置

2. 利用消息总线触发一个服务端ConfigServer的/bus/refresh端点,而刷新所有客户端的配置（更加推荐）

图二的架构显然更加合适，图一不适合的原因如下

打破了微服务的职责单一性，因为微服务本身是业务模块，它本不应该承担配置刷新职责

破坏了微服务各节点的对等性

有一定的局限性。例如，微服务在迁移时，它的网络地址常常会发生变化，此时如果想要做到自动刷新，那就会增加更多的修改

给cloud-config-center-3344配置中心服务端添加消息总线支持

pom

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

yml

server:
  port: 3344
spring:
  application:
    name: cloud-config-center
  cloud:
    config:
      server:
        git:
          uri:  https://github.com/hhf19906/springcloud-config.git  #git@github.com:hhf19906/springcloud-config.git
          search-paths:
            - springcloud-config
      label: master

rabbitmq:
    host: localhost
    port: 5672
    username: guest
    password: guest

eureka:
  client:
    service-url:
      defaultZone:  http://localhost:7001/eureka

management:
  endpoints:
    web:
      exposure:
        include: 'bus-refresh'

给cloud-config-center-3355客户端添加消息总线支持

pom

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

bootstrap.yml

server:
  port: 3355

spring:
  application:
    name: config-client
  cloud:
    config:
      label: master
      name: config
      profile: dev
      uri: http://localhost:3344

rabbitmq:
    host: localhost
    port: 5672
    username: guest
    password: guest

eureka:
  client:
    service-url:
      defaultZone: http://eureka7001.com:7001/eureka
management:
  endpoints:
    web:
      exposure:
        include: "*"

给cloud-config-center-3366客户端添加消息总线支持

pom

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

yml

server:
  port: 3366

spring:
  application:
    name: config-client
  cloud:
    config:
      label: master
      name: config
      profile: dev
      uri: http://localhost:3344


  rabbitmq:
    host: localhost
    port: 5672
    username: guest
    password: guest

eureka:
  client:
    service-url:
      defaultZone:  http://localhost:7001/eureka

management:
  endpoints:
    web:
      exposure:
        include: '*'

测试

运维工程师

修改Github上配置文件增加版本号

发送Post请求

curl -X POST "http://localhost:3344/actuator/bus-refresh"

配置中心

http://config-3344.com/config-dev.yml

客户端

http://localhost:3355/configInfo
http://localhost:3366/configInfo

获取配置信息，发现都已经刷新了

一次发送，处处生效

SpringCloud Bus动态刷新定点通知

不想全部通知，只想定点通知,只通知3355, 不通知3366

简单一句话. 指定具体某一个实例生效而不是全部

公式：http://localhost:配置中心的端口号/actuator/bus-refresh/{destination}

/bus/refresh请求不再发送到具体的服务实例上，而是发给config server并通过destination参数类指定需要更新配置的服务或实例

我们这里以刷新运行在3355端口上的config-client为例. 只通知3355, 不通知3366

curl -X POST "http://localhost:3344/actuator/bus-refresh/config-client:3355"

通知总结All