Redis HyperLogLog数据统计轻量级解决方案详解

// Redis HyperLogLog 操作示例
Jedis jedis = new Jedis("localhost");
String key = "page_views";
// 添加元素
jedis.pfadd(key, "user1");
jedis.pfadd(key, "user2");
// 获取估算的唯一元素数量
long count = jedis.pfcount(key);
System.out.println("Estimated unique elements: " + count);
// 合并 HyperLogLog
String otherKey = "more_page_views";
jedis.pfadd(otherKey, "user3");
jedis.pfmerge(key, otherKey);
// 再次获取估算数量
long mergedCount = jedis.pfcount(key);
System.out.println("Estimated unique elements after merge: " + mergedCount);

import redis.clients.jedis.Jedis;
public class UVCounter {
    private Jedis jedis;
    private String static final String BUSINESS_ID = "business_id";
    public UVCounter(String host, int port) {
        this.jedis = new Jedis(host, port);
    }
    public void addVisit(String date, String deviceUID) {
        String key = "uv:" + date;
        jedis.pfadd(key, deviceUID);
    }
    public long getUVCount(String date) {
        String key = BUSINESS_ID + ":" + "uv:" + date;
        return jedis.pfcount(key);
    }
    public static void main(String[] args) {
        UVCounter uvCounter = new UVCounter("localhost", 6379);
        // 假设这是今天的日期
        String today = "2023-12-16";
        // 模拟一些用户访问
        uvCounter.addVisit(today, "device1");
        uvCounter.addVisit(today, "device2");
        uvCounter.addVisit(today, "device3");
        uvCounter.addVisit(today, "device1"); // 重复的设备 UID
        // 获取今天的 UV 数
        long uvCount = uvCounter.getUVCount(today);
        System.out.println("Unique Visitors Today: " + uvCount);
    }
}