Ribbon实现Cloud负载均衡

安装Zookeeper要先安装JDK环境

解压

tar -zxvf /usr/local/develop/jdk-8u191-linux-x64.tar.gz -C /usr/local/develop

配置JAVA_HOME

vim /etc/profile

export JAVA_HOME=/usr/local/develop/jdk1.8.0_191

export PATH=$JAVA_HOME/bin:$PATH

export CLASSPATH=.:$JAVA_HOME/lib

让环境变量生效

source /etc/profile

java -version 查看jdk版本 至此JDK安装完成

which java 查看调用的是安装在哪里的java

做Zookeeper做服务治理(安装Zookeeper)

Apache ZooKeeperhttps://zookeeper.apache.org/

进入Zookeeper 包目录

cd /usr/local/develop/

解压

tar -zxvf apache-zookeeper-3.9.1-bin.tar.gz -C /usr/local/develop

进入配置文件  

cd /usr/local/develop/apache-zookeeper-3.9.1-bin/conf

复制文件

cp zoo_sample.cfg zoo.cfg

编辑文件 

vim zoo.cfg

现在可以进入bin目录直接启动

cd /usr/local/develop/apache-zookeeper-3.9.1-bin/bin

启动Zookeeper

./zkServer.sh start

如果需要配置Zookeeper为系统服务

vim /etc/systemd/system/zookeeper.service

[Unit]
Description=Apache ZooKeeper server
After=network.target

[Service]
Type=forking
ExecStart=/usr/local/develop/apache-zookeeper-3.9.1-bin/bin/zkServer.sh start
ExecStop=/usr/local/develop/apache-zookeeper-3.9.1-bin/bin/zkServer.sh stop
User=root
Group=root
Restart=on-failure
Environment="JAVA_HOME=/usr/local/develop/jdk1.8.0_191"

[Install]
WantedBy=multi-user.target

是配置生效

systemctl daemon-reload

开机自启  看自己实际需要

systemctl enable zookeeper.service

systemctl start zookeeper.service    启动
systemctl stop zookeeper.service    停止
systemctl restart zookeeper.service    重启
systemctl status zookeeper.service   查看状态

admin.serverPort=8888指定了ZooKeeper的管理服务器端口。这个管理服务器提供了一个简单的HTTP接口，用于获取ZooKeeper服务的状态和性能指标等信息。通过访问这个端口，你可以获取到ZooKeeper实例的各种管理信息，比如运行状态、连接数、节点数量等。

默认情况下，ZooKeeper的管理界面并不提供一个全面的Web界面来浏览这些信息，而是提供了一个简单的HTTP服务，通过发送HTTP请求到这个端口，可以获取到JSON格式的状态信息。

IP:8888/commands/stat

搭建Cloud项目

创建父项目,只做依赖版本管理

pom.xml

 <!-- 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><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId><version>2.2.2.RELEASE</version><configuration><fork>true</fork><addResources>true</addResources></configuration></plugin></plugins></build>

生产者模块

pom.xml

 <dependencies><!-- 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.cloud/spring-cloud-starter-zookeeper-discovery --><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-zookeeper-discovery</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></dependencies>

application.yml

server:port: 8081spring:application:name: cloud-provider-paymentcloud:zookeeper:connect-string: 222.22.22.2:2181

启动类

业务类

按相同套路 再创建个8082

消费者模块

依赖

 <dependencies><!-- 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.cloud/spring-cloud-starter-zookeeper-discovery --><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-zookeeper-discovery</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></dependencies>

启动类

业务类

配置类

虽然没有直接引入Ribbon  Ribbon依赖通过以下依赖已经在了

 <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-zookeeper-discovery</artifactId>
</dependency>

application.yml

如何改变Ribbon负载均衡策略

啥意思??

就是要放在启动类扫描不到的地方

重启8083消费者  可以自己多点点   现在是随机的

如果需要恢复轮询可以将启动类上的@RibbonClient注释掉

这样即使MySlefRule这个类存在,也没有效果   因为在启动类所在包以外

Ribbon负载均衡原理

负载均衡算法:rest接口第几次请求数%服务器集群总数量=实际调用服务器位置下标,每次服务重启后Rest接口计数从1开始

上面 生产者总共2个实例

List   2个实例

index=1

1%2=1    这个1  做为list.get(1%2)

index变成2

2%2=0   这个0  做为list.get(1%2)

index变成3

3%2=1   这个1  做为list.get(3%2)

index变成4

4%2=0   这个0  做为list.get(4%2)

以此类推