1. 程式人生 > >Zookeeper實現負載均衡原理

Zookeeper實現負載均衡原理

先玩個正常的,好玩的socket程式設計:

服務端:

package com.toov5.zkDubbo;

import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;

import org.I0Itec.zkclient.ZkClient;

//##ServerScoekt服務端
public class ZkServerScoekt implements Runnable {
    private static int port = 18080;  //socket 服務啟動後的所使用的 埠號
public static void main(String[] args) throws IOException { ZkServerScoekt server = new ZkServerScoekt(port); //建構函式傳入port // regServer(); //去zk註冊 Thread thread = new Thread(server); thread.start(); } public ZkServerScoekt(int port) { this.port = port; }
// //註冊服務 // public static void regServer(){ // //1、建立zk連線 // ZkClient zkClient = new ZkClient("192.168.91.5",5000,10000); // //2.先建立父節點 // String root = "/toov5"; // if (!zkClient.exists(root)) { // //如果父節點不存,直接建立父節點 // zkClient.createPersistent(root); //持久節點 // } // //3、建立子節點 // String nodeName = root+"/service_"+port;
// String nodeValue="127.0.0.1:"+port; // if (zkClient.exists(nodeName)) { //如果存在 直接刪除掉 // zkClient.delete(nodeName); // } // zkClient.createEphemeral(nodeName); //位元組的 臨時節點 如果服務宕機了 找不到了就 // System.out.println("服務註冊成功"+nodeName); // // } // // public void run() { ServerSocket serverSocket = null; try { serverSocket = new ServerSocket(port); System.out.println("Server start port:" + port); Socket socket = null; while (true) { socket = serverSocket.accept(); new Thread(new ServerHandler(socket)).start(); } } catch (Exception e) { e.printStackTrace(); } finally { try { if (serverSocket != null) { serverSocket.close(); } } catch (Exception e2) { } } } }

客戶端:

package com.toov5.zkDubbo;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
import java.util.ArrayList;
import java.util.List;

public class ZkServerClient {
    public static List<String> listServer = new ArrayList<String>();

    public static void main(String[] args) {
        initServer();
        ZkServerClient     client= new ZkServerClient();
        BufferedReader console = new BufferedReader(new InputStreamReader(System.in));
        while (true) {
            String name;
            try {
                name = console.readLine();
                if ("exit".equals(name)) {
                    System.exit(0);
                }
                client.send(name);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    // 註冊所有server 
    public static void initServer() {
        listServer.clear();
        listServer.add("127.0.0.1:18080"); //連線服務 放到list中   存放叢集地址 做負載均衡用的
    }

    // 獲取當前server資訊
    public static String getServer() {
        return listServer.get(0);
    }
    
    public void send(String name) {

        String server = ZkServerClient.getServer();
        String[] cfg = server.split(":"); 

        Socket socket = null;
        BufferedReader in = null;
        PrintWriter out = null;
        try {
            socket = new Socket(cfg[0], Integer.parseInt(cfg[1]));
            in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            out = new PrintWriter(socket.getOutputStream(), true);

            out.println(name);
            while (true) {
                String resp = in.readLine();
                if (resp == null)
                    break;
                else if (resp.length() > 0) {
                    System.out.println("Receive : " + resp);
                    break;
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (out != null) {
                out.close();
            }
            if (in != null) {
                try {
                    in.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (socket != null) {
                try {
                    socket.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

執行結果:

 

引申思路

使用Zookeeper實現負載均衡原理,伺服器端將啟動的服務註冊到,zk註冊中心上,採用臨時節點。客戶端從zk節點上獲取最新服務節點資訊,本地使用負載均衡演算法,隨機分配伺服器。

 

1、會員服務 專案啟動時候 會在zk上面建立臨時節點  /toov5 對應的value是127.0.0.1   

       如果是叢集  /toov5 下面會會以 節點形式儲存 節點名字就是IP+埠    value 分別也是 IP+埠   有些是沒有用到value的哦  

2、訂單直接去使用 /toov5 查詢下面的子節點資訊,獲取到之後。在本地使用負載均衡演算法實現呼叫,決定使用哪個。   

      127.0.0.1:8080 

      127.0.0.1:8081      

 

PS: 任何服務的底層都是 socke 技術

 

 socket客戶端 ( 客戶端去獲取註冊資訊)                                                          socket伺服器端

 

廢話不多說,專案:

          <dependencies>
		<dependency>
			<groupId>com.101tec</groupId>
			<artifactId>zkclient</artifactId>
			<version>0.8</version>
		</dependency>
	</dependencies>  

  這個不是Apache的哦注意         

 服務端程式碼:

package com.toov5.zkDubbo;

import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;

import org.I0Itec.zkclient.ZkClient;

//##ServerScoekt服務端
public class ZkServerScoekt implements Runnable {
    private static int port = 18081;  //socket 服務啟動後的所使用的 埠號

    public static void main(String[] args) throws IOException {
        ZkServerScoekt server = new ZkServerScoekt(port);  //建構函式傳入port
        regServer();  //去zk註冊
        Thread thread = new Thread(server);
        thread.start();
    }

    public ZkServerScoekt(int port) {
        this.port = port;
    }
  //註冊服務
    public static void regServer(){
        //1、建立zk連線
    ZkClient zkClient = new ZkClient("192.168.91.5",5000,10000);
        //2.先建立父節點
    String root = "/toov5";
    if (!zkClient.exists(root)) {
        //如果父節點不存,直接建立父節點
        zkClient.createPersistent(root);  //持久節點
    }
       //3、建立子節點
     String nodeName = root+"/service_"+port;      
     String nodeValue="127.0.0.1:"+port;
     if (zkClient.exists(nodeName)) {  //如果存在 直接刪除掉
        zkClient.delete(nodeName);
    }
     zkClient.createEphemeral(nodeName); //位元組的 臨時節點  如果服務宕機了 找不到了就
     System.out.println("服務註冊成功"+nodeName);
     
    }
    
    
    
    public void run() {
        ServerSocket serverSocket = null;
        try {
            serverSocket = new ServerSocket(port);
            System.out.println("Server start port:" + port);
            Socket socket = null;
            while (true) {
                socket = serverSocket.accept();
                new Thread(new ServerHandler(socket)).start();
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (serverSocket != null) {
                    serverSocket.close();
                }
            } catch (Exception e2) {

            }
        }
    }

}

客戶端程式碼:

package com.toov5.zkDubbo;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
import java.util.ArrayList;
import java.util.List;

public class ZkServerClient {
    public static List<String> listServer = new ArrayList<String>();

    public static void main(String[] args) {
        initServer();
        ZkServerClient     client= new ZkServerClient();
        BufferedReader console = new BufferedReader(new InputStreamReader(System.in));
        while (true) {
            String name;
            try {
                name = console.readLine();
                if ("exit".equals(name)) {
                    System.exit(0);
                }
                client.send(name);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    // 註冊所有server 
    public static void initServer() {
        listServer.clear();
        listServer.add("127.0.0.1:18080"); //連線服務 放到list中   存放叢集地址 做負載均衡用的
    }

    // 獲取當前server資訊
    public static String getServer() {
        return listServer.get(0);
    }
    
    public void send(String name) {

        String server = ZkServerClient.getServer();
        String[] cfg = server.split(":"); 

        Socket socket = null;
        BufferedReader in = null;
        PrintWriter out = null;
        try {
            socket = new Socket(cfg[0], Integer.parseInt(cfg[1]));
            in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            out = new PrintWriter(socket.getOutputStream(), true);

            out.println(name);
            while (true) {
                String resp = in.readLine();
                if (resp == null)
                    break;
                else if (resp.length() > 0) {
                    System.out.println("Receive : " + resp);
                    break;
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (out != null) {
                out.close();
            }
            if (in != null) {
                try {
                    in.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (socket != null) {
                try {
                    socket.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

 

啟動服務端後的結果:

可以看到 去zk註冊了資訊。服務的名字 和子節點 

 其中子節點是 臨時節點 相當於如果服務宕機了 就查不到了哦

 

啟動三次服務端後:

 

 然後 去zk讀取節點資訊:

客戶端  負載均衡輪訓演算法   

請求次數 %  服務端數 = 伺服器埠號的奇數偶數

客戶端:

package com.toov5.zkDubbo;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
import java.util.ArrayList;
import java.util.List;

import org.I0Itec.zkclient.ZkClient;

public class ZkServerClient {
    public static List<String> listServer = new ArrayList<String>();

    public static void main(String[] args) {
        initServer();
        ZkServerClient     client= new ZkServerClient();
        BufferedReader console = new BufferedReader(new InputStreamReader(System.in));
        while (true) {
            String name;
            try {
                name = console.readLine();
                if ("exit".equals(name)) {
                    System.exit(0);
                }
                client.send(name);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    // 註冊所有server 
    public static void initServer() {
        listServer.clear();
//        listServer.add("127.0.0.1:18080"); //連線服務 放到list中   存放叢集地址 做負載均衡用的   
        //建立zk連線
        ZkClient zkClient = new ZkClient("192.168.91.5",5000,10000);
        //讀取父節點資訊
        String root = "/toov5";
        List<String> children=zkClient.getChildren(root);
        for(String pString : children){
            //父+子 =完整的路徑
            String path = root+"/"+pString;
            String nodeValue =zkClient.readData(path);
            //把值放到集合中去
            listServer.add(nodeValue);
        }
        //服務發現成功
         System.out.println("服務發現:"+listServer.toString());
         //然後給 serverCount賦值
         serverCount=listServer.size();
         
    }
 
  //請求總數
    private static  int  reqCount = 1;
  //服務個數    
    private static int  serverCount = 0; //初始值是0
    
    // 獲取當前server資訊
    public static String getServer() {
//        return listServer.get(0);  不能寫死  本地負載均衡輪詢演算法
    String serverName = listServer.get(reqCount%serverCount );
    System.out.println("客戶端請求次數:"+reqCount+"對應伺服器"+serverName);
    reqCount++;
    return serverName;    
    }
    
    public void send(String name) {

        String server = ZkServerClient.getServer();
        String[] cfg = server.split(":"); 

        Socket socket = null;
        BufferedReader in = null;
        PrintWriter out = null;
        try {
            socket = new Socket(cfg[0], Integer.parseInt(cfg[1]));
            in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            out = new PrintWriter(socket.getOutputStream(), true);

            out.println(name);
            while (true) {
                String resp = in.readLine();
                if (resp == null)
                    break;
                else if (resp.length() > 0) {
                    System.out.println("Receive : " + resp);
                    break;
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (out != null) {
                out.close();
            }
            if (in != null) {
                try {
                    in.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (socket != null) {
                try {
                    socket.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

啟動後(後端服務啟動三個):

 

訪問一次:取模演算法後的結果

第二次、第三次:

 

 看到結果 太美妙了!

美妙集中在此:

 

好好欣賞下~~