详解Java实现负载均衡的几种算法代码

本篇文章主要介绍java实现负载均衡的几种算法，具体如下：

轮询:

package class2.zookeeper.loadbalance;

import java.util.arraylist;
import java.util.hashmap;
import java.util.map;
import java.util.set;

/**
 * 負載均衡算法，輪詢法
 * @author guoy
 *
 */
public class testroundrobin {

  
  static map<string,integer> serverweigthmap = new hashmap<string,integer>();

   static{
    serverweigthmap.put("192.168.1.12", 1);
    serverweigthmap.put("192.168.1.13", 1);
    serverweigthmap.put("192.168.1.14", 2);
    serverweigthmap.put("192.168.1.15", 2);
    serverweigthmap.put("192.168.1.16", 3);
    serverweigthmap.put("192.168.1.17", 3);
    serverweigthmap.put("192.168.1.18", 1);
    serverweigthmap.put("192.168.1.19", 2);
  }
   integer pos = 0;
   public string roundrobin()
    {
      //重新建立一個map,避免出現由於服務器上線和下線導致的並發問題
      map<string,integer> servermap = new hashmap<string,integer>();
      servermap.putall(serverweigthmap);
      //獲取ip列表list
      set<string> keyset = servermap.keyset();
      arraylist<string> keylist = new arraylist<string>();
      keylist.addall(keyset);
      
      string server = null;
      
      synchronized (pos) {
        if(pos >=keyset.size()){
          pos = 0;
        }
        server = keylist.get(pos);
        pos ++;
      }
      return server;
    }
    
    public static void main(string[] args) {
      testroundrobin robin = new testroundrobin();
      for (int i = 0; i < 20; i++) {
        string serverip = robin.roundrobin();
        system.out.println(serverip);
      }
    }
}

加权轮询:

package class2.zookeeper.loadbalance;

import java.util.arraylist;
import java.util.hashmap;
import java.util.iterator;
import java.util.list;
import java.util.map;
import java.util.random;
import java.util.set;

/**
 * 加權隨機载均衡算法
 * @author guoy
 *
 */
public class testweightrandom {
  
  static map<string,integer> serverweigthmap = new hashmap<string,integer>();

   static{
    serverweigthmap.put("192.168.1.12", 1);
    serverweigthmap.put("192.168.1.13", 1);
    serverweigthmap.put("192.168.1.14", 2);
    serverweigthmap.put("192.168.1.15", 2);
    serverweigthmap.put("192.168.1.16", 3);
    serverweigthmap.put("192.168.1.17", 3);
    serverweigthmap.put("192.168.1.18", 1);
    serverweigthmap.put("192.168.1.19", 2);
  }

  public static string weightrandom()
  {
    //重新建立一個map,避免出現由於服務器上線和下線導致的並發問題
    map<string,integer> servermap = new hashmap<string,integer>();
    servermap.putall(serverweigthmap);
    //獲取ip列表list
    set<string> keyset = servermap.keyset();
    iterator<string> it = keyset.iterator();

    list<string> serverlist = new arraylist<string>();

    while (it.hasnext()) {
      string server = it.next();
      integer weight = servermap.get(server);
      for (int i = 0; i < weight; i++) {
        serverlist.add(server);
      }
    }    
    random random = new random();
    int randompos = random.nextint(serverlist.size());
    
    string server = serverlist.get(randompos);
    return server;
  }
  
  public static void main(string[] args) {
    string serverip = weightrandom();
    system.out.println(serverip);
  }
}

随机:

package class2.zookeeper.loadbalance;

import java.util.arraylist;
import java.util.hashmap;
import java.util.map;
import java.util.random;
import java.util.set;

/**
 * 隨機负载均衡算法
 * @author guoy
 *
 */
public class testrandom {
  
  static map<string,integer> serverweigthmap = new hashmap<string,integer>();

   static{
    serverweigthmap.put("192.168.1.12", 1);
    serverweigthmap.put("192.168.1.13", 1);
    serverweigthmap.put("192.168.1.14", 2);
    serverweigthmap.put("192.168.1.15", 2);
    serverweigthmap.put("192.168.1.16", 3);
    serverweigthmap.put("192.168.1.17", 3);
    serverweigthmap.put("192.168.1.18", 1);
    serverweigthmap.put("192.168.1.19", 2);
  }

  public static string random()
  {
    //重新建立一個map,避免出現由於服務器上線和下線導致的並發問題
    map<string,integer> servermap = new hashmap<string,integer>();
    servermap.putall(serverweigthmap);
    //獲取ip列表list
    set<string> keyset = servermap.keyset();
    arraylist<string> keylist = new arraylist<string>();
    keylist.addall(keyset);
    
    random random = new random();
    int randompos = random.nextint(keylist.size());
    
    string server = keylist.get(randompos);
    return server;
  }
  
  public static void main(string[] args) {
    string serverip = random();
    system.out.println(serverip);
  }
}

加权随机:

package class2.zookeeper.loadbalance;

import java.util.arraylist;
import java.util.hashmap;
import java.util.iterator;
import java.util.list;
import java.util.map;
import java.util.random;
import java.util.set;

/**
 * 加權隨機载均衡算法
 * @author guoy
 *
 */
public class testweightrandom {
  
  static map<string,integer> serverweigthmap = new hashmap<string,integer>();

   static{
    serverweigthmap.put("192.168.1.12", 1);
    serverweigthmap.put("192.168.1.13", 1);
    serverweigthmap.put("192.168.1.14", 2);
    serverweigthmap.put("192.168.1.15", 2);
    serverweigthmap.put("192.168.1.16", 3);
    serverweigthmap.put("192.168.1.17", 3);
    serverweigthmap.put("192.168.1.18", 1);
    serverweigthmap.put("192.168.1.19", 2);
  }

  public static string weightrandom()
  {
    //重新建立一個map,避免出現由於服務器上線和下線導致的並發問題
    map<string,integer> servermap = new hashmap<string,integer>();
    servermap.putall(serverweigthmap);
    //獲取ip列表list
    set<string> keyset = servermap.keyset();
    iterator<string> it = keyset.iterator();

    list<string> serverlist = new arraylist<string>();

    while (it.hasnext()) {
      string server = it.next();
      integer weight = servermap.get(server);
      for (int i = 0; i < weight; i++) {
        serverlist.add(server);
      }
    }    
    random random = new random();
    int randompos = random.nextint(serverlist.size());
    
    string server = serverlist.get(randompos);
    return server;
  }
  
  public static void main(string[] args) {
    string serverip = weightrandom();
    system.out.println(serverip);
  }
}

ip hash:

package class2.zookeeper.loadbalance;

import java.util.arraylist;
import java.util.hashmap;
import java.util.map;
import java.util.set;

/**
 * 负载均衡 ip_hash算法
 * @author guoy
 *
 */
public class testiphash {

  
  static map<string,integer> serverweigthmap = new hashmap<string,integer>();

   static{
    serverweigthmap.put("192.168.1.12", 1);
    serverweigthmap.put("192.168.1.13", 1);
    serverweigthmap.put("192.168.1.14", 2);
    serverweigthmap.put("192.168.1.15", 2);
    serverweigthmap.put("192.168.1.16", 3);
    serverweigthmap.put("192.168.1.17", 3);
    serverweigthmap.put("192.168.1.18", 1);
    serverweigthmap.put("192.168.1.19", 2);
  }

   /**
   * 获取请求服务器地址
   * @param remoteip 负载均衡服务器ip
   * @return
   */
  public static string iphash(string remoteip)
  {
    //重新建立一個map,避免出現由於服務器上線和下線導致的並發問題
    map<string,integer> servermap = new hashmap<string,integer>();
    servermap.putall(serverweigthmap);
    //獲取ip列表list
    set<string> keyset = servermap.keyset();
    arraylist<string> keylist = new arraylist<string>();
    keylist.addall(keyset);
    
    int hashcode =remoteip.hashcode();
    int serverlistsize = keylist.size();
    int serverpos = hashcode % serverlistsize;
    
    return keylist.get(serverpos);
  }
  
  public static void main(string[] args) {
    string serverip = iphash("192.168.1.12");
    system.out.println(serverip);
  }

}

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