负载均衡的几种算法Java实现代码
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); } }