Zookeeper實現負載均衡原理
阿新 • • 發佈:2018-11-03
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~~