微服务间通信重构与服务治理笔记

父工程

依赖版本管理,但实际不引入依赖

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.example</groupId>
    <artifactId>SpringCloud</artifactId>
    <version>1.0-SNAPSHOT</version>
   
    <packaging>pom</packaging>
    <!-- 统一管理jar包版本 -->
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <junit.version>4.12</junit.version>
        <log4j.version>1.2.17</log4j.version>
        <lombok.version>1.16.18</lombok.version>
        <mysql.version>5.1.47</mysql.version>
        <druid.version>1.1.16</druid.version>
        <mybatis.spring.boot.version>1.3.0</mybatis.spring.boot.version>
    </properties>


    <!-- 子模块继承之后，提供作用：锁定版本+子modlue不用写groupId和version  -->
    <dependencyManagement>
        <dependencies>
            <!--spring boot 2.2.2-->
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>2.2.2.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!--spring cloud Hoxton.SR1-->
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Hoxton.SR1</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!--spring cloud alibaba 2.1.0.RELEASE-->
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>2.1.0.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>

            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>${mysql.version}</version>
            </dependency>
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>druid</artifactId>
                <version>${druid.version}</version>
            </dependency>
            <dependency>
                <groupId>org.mybatis.spring.boot</groupId>
                <artifactId>mybatis-spring-boot-starter</artifactId>
                <version>${mybatis.spring.boot.version}</version>
            </dependency>
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>${junit.version}</version>
            </dependency>
            <dependency>
                <groupId>log4j</groupId>
                <artifactId>log4j</artifactId>
                <version>${log4j.version}</version>
            </dependency>
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <version>${lombok.version}</version>
                <optional>true</optional>
            </dependency>

        </dependencies>
    </dependencyManagement>

    <build>
        <finalName>cloud</finalName>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>2.2.2.RELEASE</version> <!-- 与Spring Boot版本对应 -->
                <configuration>
                    <fork>true</fork>
                    <addResources>true</addResources>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

支付模块

server:
  port: 8081

spring:
  application:
    name: cloud-payment-service
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: org.gjt.mm.mysql.Driver
    url: jdbc:mysql://xxxx:3306/db2019?useUnicode=true&characterEncoding=utf-8&useSSL=false
    username: xxxx
    password: xxxxxxx

mybatis:
  mapperLocations: classpath:mappers/*.xml
  #这些Java Bean在mapper XML文件中可以使用别名代替全限定类名
  type-aliases-package: com.example.commons.pojo
logging:
  level:
    com:
      example:
        pay:
          mapper: debug

#将服务注册到Eureka
eureka:
  client:
    #表示是否将自己注册进EurekaServer默认为true
    register-with-eureka: true
    #是否从EurekaServer抓取已有的注册信息默认true 单节点无所谓,集群必须设置为true才能配合ribbon使用负载均衡
    fetchRegistry: true
    service-url:
      #defaultZone: http:http://eureka7001.com:7001/eureka/
      #集群版
      defaultZone: http://eureka7001.com:7001/eureka/,http://eureka7002.com:7002/eureka/

模块结构

依赖 eureka client是后期要用的

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>SpringCloud</artifactId>
        <groupId>org.example</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>cloud-provider-payment8081</artifactId>

    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
        <dependency>
            <groupId>org.example</groupId>
            <artifactId>cloud-api-commons</artifactId>
            <version>${project.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-web -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-web -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-web -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.2.2</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/com.alibaba/druid -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.10</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-jdbc -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-devtools -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-test -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-devtools -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
    </dependencies>

</project>

pojo

映射文件因后期重构以移动到commons

<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.example.pay.mapper.PaymentMapper">

    <insert id="createPayment" useGeneratedKeys="true" keyProperty="id">
        insert into payment(serial)value(#{serial})
    </insert>

    <select id="getPaymentById" resultType="com.example.commons.pojo.payment">
        select * from payment where id=#{id}
    </select>
</mapper>

控制器

订单模块

在父工程下创建moudle

配置RestTemplate

调用支付模块

application.yml

server:
  port: 80

spring:
  application:
    name: cloud-consumer-ord
#将服务注册到Eureka
eureka:
  client:
    #表示是否将自己注册进EurekaServer默认为true
    register-with-eureka: true
    #是否从EurekaServer抓取已有的注册信息默认true 单节点无所谓,集群必须设置为true才能配合ribbon使用负载均衡
    fetchRegistry: true
    service-url:
      #defaultZone: http://localhost:7001/eureka
      #集群版
      defaultZone: http://eureka7001.com:7001/eureka/,http://eureka7002.com:7002/eureka/

将支付和订单的pojo单独重构放到commons模块并在支付和订单模块分别引入

Eureka服务治理

SpringCloud封装了Netflix公司的Eureka模块来实现服务治理

Eureka是服务发现与治理的一套解决方案还有Nacos Zookeeper Sofa Consul Etcd

在传统的RPC远程调用(如Dubbo,RestTemplate不属于RPC调用)框架中,管理每个服务与服务之间依赖关系比较复杂,所以需要服务治理.实现服务发现与注册.Eureka维护一个服务注册表,其他服务可以查询这个注册表来发现和调用其他微服务.

Eureka使得各个微服务之间能够相互发现并进行通信,但它本身不提供远程调用的功能

Eureka采用CS设计架构.Eureka Server做为服务注册功能的服务器.它是服务注册中心,而系统中的其他微服务,使用Eureka的客户端连接到Eureka的Server并通过心跳连接检测.这样系统的维护人员就可以通过Eureka Server来监控系统中各个微服务是否正常运行.

在服务注册与发现中,有一个注册中心,当服务器启动的时候,会把当前自己服务器的信息,比如服务器通讯地址等以别名方式注册到注册中心.消费者可通过注册中心获取服务通信地址.然后通过RPC调用.任何RPC远程调用框架都会有一个注册中心(存放服务地址相关信息包括接口地址)

Eureka包含两个组件:Eureka Server和Eureka Client

Eureka Server提供服务注册

各个微服务节点通过配置启动之后,会在EurekaServer进行注册,这样EurekaServer中的服务注册表中将存储可用服务的节点信息.

Eureka Client通过注册中心访问

是一个Java客户端,为了简化EurekaServer的交互,客户端同时也具备一个内置的,使用轮询(round-robin)负载算法的负载均衡器.应用启动后,将会向Eureka Server发送心跳(默认30秒发送一次).如果Eureka Server在多个心跳周期内没有接收到某个节点发送的心跳.EurekaServer将会从服务注册表中将该节点移除(默认90秒)

单机版Eureka服务注册中心构建

@EnableEurekaServer表示我是一个EurekaServer

application.yml

server:
  port: 7001

eureka:
  instance:
    hostname: localhost  # eureka服务端的实例名称
  client:
    # 表示不向注册中心注册自己
    register-with-eureka: false
    # 表示自己就是注册中心，职责是维护服务实例，并不需要去检索服务
    fetch-registry: false
    service-url:
      # 设置与eureka server交互的地址查询服务和注册服务都需要依赖这个地址  ${}是上面定义的
      defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>SpringCloud</artifactId>
        <groupId>org.example</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>cloud-eureka-server-7001</artifactId>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>
    <dependencies>
        <!-- https://mvnrepository.com/artifact/org.springframework.cloud/spring-cloud-starter-eureka-server -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
        </dependency>

        <dependency>
            <groupId>org.example</groupId>
            <artifactId>cloud-api-commons</artifactId>
            <version>${project.version}</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-web -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-web  -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-devtools -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-test -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
        </dependency>

    </dependencies>
</project>

localhost:7001/

支付模块完成服务注册

首先引入依赖

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>

启动类加上客户端注解

application.yml

#将服务注册到Eureka
eureka:
  client:
    #表示是否将自己注册进EurekaServer默认为true
    register-with-eureka: true
    #是否从EurekaServer抓取已有的注册信息默认true 单节点无所谓,集群必须设置为true才能配合ribbon使用负载均衡
    fetchRegistry: true
    service-url:
      defaultZone: http://localhost:7001/eureka

订单模块完成服务注册

依赖

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>

访问 localhost:7001/

Eureka服务治理集群构建

目的高可用,如果单个Eureka服务挂了,会导致整个服务环境不可用

搭建Eureka注册中心集群,实现负载均衡+故障容错

比如有两台Eureka服务 7001和7002

那就是相互注册

如果是三台 7001 7002 7003

那么就是7001注册 7002和7003 7002注册7001和7003 7003注册7001和7002

两两相望相互注册

为了看的清除

C:\Windows\System32\drivers\etc\hosts

127.0.0.1 eureka7001.com
127.0.0.1 eureka7002.com

pom.xml

<dependencies>
    <!-- https://mvnrepository.com/artifact/org.springframework.cloud/spring-cloud-starter-eureka-server -->
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
    </dependency>

    <dependency>
        <groupId>org.example</groupId>
        <artifactId>cloud-api-commons</artifactId>
        <version>${project.version}</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-web -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-web  -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-actuator</artifactId>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-devtools -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <scope>runtime</scope>
        <optional>true</optional>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-test -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
    </dependency>

</dependencies>

主启动类

application.yml配置文件需要相互注册

server:
  port: 7002


eureka:
  instance:
    hostname: eureka7002.com  # eureka服务端的实例名称
  client:
    # 表示不向注册中心注册自己
    register-with-eureka: false
    # 表示自己就是注册中心，职责是维护服务实例，并不需要去检索服务
    fetch-registry: false
    service-url:
      # 设置与eureka server交互的地址查询服务和注册服务都需要依赖这个地址  ${}是上面定义的
      #defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/
      defaultZone: http://eureka7001.com:7001/eureka/

在原先7001的application里修改配置