mysql实现高并发计数器
因为在高并发下 set aa=aa+1要进行锁表 不然会计算错误 但是锁表了 性能就降低了 所以 计数器采用另外一种方案
CREATE TABLE `article_view`( `article_id` int(11) NOT NULL, `pond` tinyint(4) NOT NULL COMMENT '池子,就是用来随机用的', `view` int(11) NOT NULL, PRIMARY KEY (`article_id`,`pond`) )ENGINE=InnoDB;
INSERT INTO `article_view` (`article_id`, `pond`, `view`) VALUES (123, RAND()*100, 1) ON DUPLICATE KEY UPDATE `view`=`view`+1
SELECT SUM(`view`) FROM `article_view` WHERE `article_id`=123
查询出来的数据再更新到字段
如果希望减少表的行数,以避免表变得太大,可以写一个周期执行的任务,合并所有结果到0 号槽,并且删除所有其他的槽: UPDATE daily_hit_counter as c INNER JOIN ( SELECT day, SUM(cnt) AS cnt, MIN(slot) AS mslot FROM daily_hit_counter GROUP BY day ) AS x USING(day) SET c.cnt = IF(c.slot = x.mslot, x.cnt, 0), c.slot = IF(c.slot = x.mslot, 0, c.slot); DELETE FROM daily_hit_counter WHERE slot <> 0 AND cnt = 0;
原创文章,作者:ItWorker,如若转载,请注明出处:https://blog.ytso.com/4018.html