Centos zookeeper集群 dubbo 使用

前言

ZooKeeper是一个分布式的，开放源码的分布式应用程序协调服务，是Google的Chubby一个开源的实现，是Hadoop和Hbase的重要组件。它是一个为分布式应用提供一致性服务的软件，提供的功能包括：配置维护、域名服务、分布式同步、组服务等 [ 百度百科 ]

开始

1 .去官网，下载 ZooKeeper

 cd    /usr/local/
 wget  http://mirror.bit.edu.cn/apache/zookeeper/zookeeper-3.5.2-alpha/zookeeper-3.5.2-alpha.tar.gz

2 .创建文件夹，解压压缩包

 mkdir  -p  /usr/local/zookeeper
 tar  -zxvf  zookeeper-3.5.2-alpha.tar.gz -C /usr/local/zookeeper

3 .配置zookeeper文件

 cd  /usr/local/zookeeper/zookeeper-3.5.2-alpha/conf/
 cp  zoo_sample.cfg zoo.cfg
 vi  /usr/local/zookeeper/zookeeper-3.5.2-alpha/conf/zoo.cfg

配置如下：

dataDir=/usr/local/zookeeper/zookeeper-3.5.2-alpha/data/
server.1=192.168.0.118:2888:3888
server.2=192.168.0.120:2888:3888
server.3=192.168.0.121:2888:3888

注意，这里的server.1(myid)，需要在 /usr/local/zookeeper/zookeeper-3.5.2-alpha/data/下面创建文件名为 myid 内容是 1 来标识服务器

4 .配置环境变量，在zookeeper文件后面附加如下配置

 vi /etc/profile

配置如下：

 # idea - zookeeper-3.5.2 config start - 2017-09-01

   export ZOOKEEPER_HOME=/usr/local/zookeeper/zookeeper-3.5.2-alpha/
   export PATH=$ZOOKEEPER_HOME/bin:$PATH
   export PATH

 # idea - zookeeper-3.5.2 config start - 2017-09-01

5 .刷新配置文件，并启动

  source       /etc/profile
  cd           /usr/local/zookeeper/zookeeper-3.5.2-alpha/bin/
  zkServer.sh  start
  zkServer.sh  status
  zkServer.sh  start-foreground  -- 启动错误信息 

6 .如果查看状态报错，请关闭防火墙，命令如下

  systemctl stop firewalld
  systemctl disable firewalld

8 .成功状态如下

[root@localhost bin]#   zkServer.sh  status
/usr/bin/java
ZooKeeper JMX enabled by default
Using config: /usr/local/zookeeper/zookeeper-3.5.2-alpha/bin/../conf/zoo.cfg
Client port found: 2181. Client address: localhost.
Mode: follower

9 .dubbo中provider.xml配置如下：

    <dubbo:application name="hello-world-app"/>
    <dubbo:registry  protocol="zookeeper"  address="192.168.0.118:2181,192.168.0.120:2181,192.168.0.121:2181"  />
    <dubbo:service interface="com.alvis.service.interfaces.IDemoService" ref="demoService"  loadbalance="roundrobin"/>
    <bean id="demoService" class="com.alvis.service.implementes.DemoService"/>

pom.xml中配置如下：

   <dependencies>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>dubbo</artifactId>
            <version>2.5.3</version>
        </dependency>
        <dependency>
            <groupId>com.github.sgroschupf</groupId>
            <artifactId>zkclient</artifactId>
            <version>0.1</version>
        </dependency>
    </dependencies>

10 .将服务打包成jar文件，发布到三个服务器中，使用命令开始运行服务

  java -jar /usr/local/dubbo/dubbo-provider.jar

11 .dubbo consumer多次调用可以看到如下信息，如果某个服务挂了，会自动切换到其他2个节点

Hello world, response form provider: 192.168.0.118:20880
Hello world, response form provider: 192.168.0.120:20880
Hello world, response form provider: 192.168.0.121:20880

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结束