使用zookeeper实现服务路由和负载均衡

三个类：

ServiceAProvider

ServiceBProvider

ServiceConsumer

其中

ServiceAProvider提供的服务名service-A，指向IP为192.168.58.130

ServiceBProvider提供的服务名service-A，指向IP为192.168.58.131

当有消费者请求时，随机地选取service-A列表的服务器提供服务

ServiceConsumer 为消费者类

依赖：

<dependency>
<groupId>org.apache.zookeeper</groupId>
<artifactId>zookeeper</artifactId>
<version>3.4.5-cdh5.1.0</version>
</dependency>
<dependency>
<groupId>org.apache.helix</groupId>
<artifactId>helix-core</artifactId>
<version>0.6.4</version>
</dependency>

github源码下载地址：

https://github.com/Bellonor/myhadoop2.x/tree/master/myhadoop2.x/src/main/java/com/jamesfen/zookeeper

详见下面的代码：

服务提供者ServiceAProvider类的源码为：

package com.jamesfen.zookeeper;
import java.net.InetAddress;
import org.I0Itec.zkclient.ZkClient;
public class ServiceAProvider {

private String serviceName = "service-A";

//向zookeeper注册服务
public void init() throws Exception{
String serverList = "192.168.58.11:2181";
String PATH ="/configcenter";//根节点路径
ZkClient zkClient = new ZkClient(serverList);
boolean rootExists = zkClient.exists(PATH);
if(!rootExists){
zkClient.createPersistent(PATH);
}
//判断是否存在，不存在则创建服务节点
boolean serviceExists = zkClient.exists(PATH + "/" + serviceName);
if(!serviceExists){
zkClient.createPersistent(PATH + "/" + serviceName);
}

//註冊當前服務
InetAddress addr =InetAddress.getLocalHost();
//String ip= addr.getHostAddress().toString();
String ip = "192.168.58.130";

//創建當前服務器節點
zkClient.createEphemeral(PATH + "/" + serviceName + "/" + ip);

System.out.println("提供的服务节点名称为："+PATH + "/" + serviceName + "/" + ip);
}
//提供服务
public void provide(){

}
public static void main(String[]args) throws Exception {
ServiceAProvider service = new ServiceAProvider();
service.init();

Thread.sleep(1000*60*60*24);
}

}


服务提供者ServiceBProvider类源码为
package com.jamesfen.zookeeper;
import java.net.InetAddress;
import org.I0Itec.zkclient.ZkClient;
public class ServiceBProvider {
//服务名仍然为 A,这样是为了，一个服务名有两个台机器在服务，才能做负载均衡.
private String serviceName = "service-A";

//向zookeeper注册服务
public void init() throws Exception{
String serverList = "192.168.58.11:2181";
String PATH ="/configcenter";//根节点路径
ZkClient zkClient = new ZkClient(serverList);
boolean rootExists = zkClient.exists(PATH);
if(!rootExists){
zkClient.createPersistent(PATH);
}

boolean serviceExists = zkClient.exists(PATH + "/" + serviceName);
if(!serviceExists){
zkClient.createPersistent(PATH + "/" + serviceName);//創建服務節點
}

//註冊當前服務
InetAddress addr =InetAddress.getLocalHost();
//String ip= addr.getHostAddress().toString();
String ip = "192.168.58.131";

//創建當前服務器節點
zkClient.createEphemeral(PATH + "/" + serviceName + "/" + ip);

System.out.println("提供的服务节点名称为："+PATH + "/" + serviceName + "/" + ip);
}
//提供服务
public void provide(){

}
public static void main(String[]args) throws Exception {
ServiceBProvider service = new ServiceBProvider();
service.init();

Thread.sleep(1000*60*60*24);
}

}


消费者类源码为：
package com.jamesfen.zookeeper;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import org.I0Itec.zkclient.IZkChildListener;
import org.I0Itec.zkclient.ZkClient;
public class ServiceConsumer {

private List<String> serverList = new ArrayList<String>();

private String serviceName ="service-A";

//初始化服务地址信息
public void init(){
String zkServerList ="192.168.58.11:2181";
String SERVICE_PATH="/configcenter/"+serviceName;//服务节点路径
ZkClient zkClient = new ZkClient(zkServerList);

boolean serviceExists =zkClient.exists(SERVICE_PATH);
if(serviceExists){
serverList =zkClient.getChildren(SERVICE_PATH);
}else{
throw new RuntimeException("service not exist!");
}

//注册事件监听
zkClient.subscribeChildChanges(SERVICE_PATH,new IZkChildListener(){
//@Override
public void handleChildChange(String parentPath, List<String> currentChilds)throws Exception{
serverList = currentChilds;
}
});
}

//消费服务
public void consume(){
//通过负责均衡算法，得到一台服务器进行调用
int index = getRandomNum(0,1);
System.out.println("调用" + serverList.get(index)+"提供的服务：" + serviceName);
}

public int getRandomNum(int min,int max){
Random rdm = new Random();
return rdm.nextInt(max-min+1)+min;
}

public static void main(String[] args)throws Exception {
ServiceConsumer consumer = new ServiceConsumer();

consumer.init();
consumer.consume();

Thread.sleep(1000*60*60*24);
}

}