负载均衡的几种算法

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);
}
}
}

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);
}
}

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);
}
}

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);
}
}

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);
}

}