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
- 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
- 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
