Detailed explanation of several algorithm codes for implementing load balancing in Java

This article mainly introduces several algorithm codes that explain Java's load balancing in detail. The editor thinks it is quite good, so I will share it with you now and give it as a reference. Let’s follow the editor and take a look.

This article mainly introduces several algorithms for Java to achieve load balancing, as follows:

Polling:

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);
      }
    }
}

Weighted polling:

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);
  }
}

Random:

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);
  }
}

Weighted random:

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);
  }

}

The above is the detailed explanation of several algorithm codes for Java to achieve load balancing. For more related content, please pay attention to the PHP Chinese website (www.php.cn)!