redis使用watch秒殺搶購思路
阿新 • • 發佈:2017-11-23
fixed shutdown author pub 邏輯 uid trace sets ren
1、使用watch,采用樂觀鎖
2、不使用悲觀鎖,因為等待時間非常長,響應慢
3、不使用隊列,因為並發量會讓隊列內存瞬間升高
測試代碼:
import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import redis.clients.jedis.Jedis; /** * redis測試搶購 * * @author 10255_000 * */ public class RedisTest { public static void main(String[] args) { final String watchkeys = "watchkeys"; ExecutorService executor = Executors.newFixedThreadPool(20); final Jedis jedis = new Jedis("192.168.3.202", 6379); jedis.set(watchkeys, "0");// 重置watchkeys為0 jedis.del("setsucc", "setfail");// 清空搶成功的,與沒有成功的 jedis.close(); for (int i = 0; i < 10000; i++) {// 測試一萬人同時訪問 executor.execute(new MyRunnable()); } executor.shutdown(); } }
import java.util.List; import java.util.UUID; import redis.clients.jedis.Jedis; import redis.clients.jedis.Transaction; public class MyRunnable implements Runnable { String watchkeys = "watchkeys";// 監視keys Jedis jedis = new Jedis("192.168.3.202", 6379); public MyRunnable() { } @Override public void run() { try { jedis.watch(watchkeys);// watchkeys String val = jedis.get(watchkeys); int valint = Integer.valueOf(val); String userifo = UUID.randomUUID().toString(); if (valint < 10) { Transaction tx = jedis.multi();// 開啟事務 tx.incr("watchkeys"); List<Object> list = tx.exec();// 提交事務,如果此時watchkeys被改動了,則返回null if (list != null) { System.out.println("用戶:" + userifo + "搶購成功,當前搶購成功人數:" + (valint + 1)); /* 搶購成功業務邏輯 */ jedis.sadd("setsucc", userifo); } else { System.out.println("用戶:" + userifo + "搶購失敗"); /* 搶購失敗業務邏輯 */ jedis.sadd("setfail", userifo); } } else { System.out.println("用戶:" + userifo + "搶購失敗"); jedis.sadd("setfail", userifo); // Thread.sleep(500); return; } } catch (Exception e) { e.printStackTrace(); } finally { jedis.close(); } } }
redis使用watch秒殺搶購思路