Question

我们在bash脚本中有以下MySQL任务：

INSERT INTO  blah blah blah;


ALTER TABLE table RENAME TO table_OLD;

现在MySQL INSERT查询运行超过11个小时，但仍未完成。然后ALTER表查询启动，使自己等待元数据锁定，因为INSERT查询仍在运行（根据“SHOW FULL PROCESSLIST＆amp; SHOW ENGINE INNODB STATUS”）。

当mysql插入一个达到wait_timeout限制的表时发生了什么，这是8小时。一旦达到限制，MySQL是否会在解锁插入的表时继续运行它？谢谢！

以下是一些测试：当INSERT INTO超过1秒时，INSERT INTO查询仍显示正在运行并最终完成。 “Wait_timeout”限制到底有什么作用？阅读MySQL用户手册后，我仍然很困惑。（https://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html#sysvar_wait_timeout）有什么想法吗？

SET SESSION wait_timeout = 1;

SHOW SESSION VARIABLES LIKE "wait_timeout"; -- 1

INSERT INTO  blah blah blah;


ALTER TABLE table RENAME TO table_OLD;

Answer 1

我怀疑它会断开与DB的连接，迫使你重新连接，从而切断了插件的连接

发现此网站非常有用：https://www.digitalocean.com/community/questions/how-to-set-no-timeout-to-mysql

这里只是关于从DigitalOcean删除超时的摘要

Edit your my.cnf (MySQL config file)
sudo nano /etc/mysql/my.cnf

然后

wait_timeout = 28800
interactive_timeout = 28800

The interactive timeout does not affect any web application connections. A high interactivetimeout but a low waittimeout is normal and is the best practice.

Choose a reasonable waittimeout value. Stateless PHP environments do well with a 60 second timeout or less. Stateful applications that use a connection pool (Java, .NET, etc.) will need to adjust waittimeout to match their connection pool settings. The default 8 hours (wait_timeout = 28800) works well with properly configured connection pools.

mysql插入表时发生的情况达到wait_timeout限制

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