系网站的开发和建设毕业设计网页制作网站知识
1.背景:
上线后,功能测试. 进入小程序页面发现很慢,耗时超过5秒,打开skywalking发现大量接口耗时都很高.
2.top命令
服务器top命令查看cpu资源发现占用并不高
3.mysql查看sql运行情况
# 当前运行的所有事务
select * from information_schema.innodb_trx;
1 | NULL |
| 422058432413352 | RUNNING | 2024-10-16 19:19:56 | NULL | NULL | 0 | 33722 | SELECT count(1) FROMt_account_tradeLEFT JOIN t_user u ON u.user_id = t_account_trade.user_id oru.TG_id = t_account_trade.user_id | fetching rows | 2 | 0 | 0 | 1128 | 0 | 0 | 0 | READ COMMITTED | 1 | 1 | NULL | 0 | 0 | 1 | 1 | NULL |
| 422058432416616 | RUNNING | 2024-10-16 19:00:54 | NULL | NULL | 0 | 33589 | SELECT count(1) FROMt_account_tradeLEFT JOIN t_user u ON u.user_id = t_account_trade.user_id oru.TG_id = t_account_trade.user_id | fetching rows | 2 | 0 | 0 | 1128 | 0 | 0 | 0 | READ COMMITTED | 1 | 1 | NULL | 0 | 0 | 1 | 1 | NULL |
| 422058432414984 | RUNNING | 2024-10-16 19:00:46 | NULL | NULL | 0 | 33588 | SELECT count(1) FROMt_account_tradeLEFT JOIN t_user u ON u.user_id = t_account_trade.user_id oru.TG_id = t_account_trade.user_id | fetching rows | 2 | 0 | 0 | 1128 | 0 | 0 | 0 | READ COMMITTED | 1 | 1 | NULL | 0 | 0 | 1 | 1 | NULL |大量查询sql处于running状态:
SELECT count(1) FROM
t_account_trade
LEFT JOIN t_user u ON u.user_id = t_account_trade.user_id or
u.TG_id = t_account_trade.user_id
很明显是sql里面里面加了or 导致没走索引, 线上百万数据必然会卡死 .
结合业务去掉or u.TG_id = t_account_trade.user_id ,重新发布,重启mysql,问题解决