终止空闲的 mysql 连接
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/4284194/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Terminating idle mysql connections
提问by shantanuo
I see a lot of connections are open and remain idle for a long time, say 5 minutes.
我看到很多连接都打开并长时间保持空闲状态，比如 5 分钟。
Is there any solution to terminate / close it from server without restarting the mysql service?
是否有任何解决方案可以在不重新启动 mysql 服务的情况下从服务器终止/关闭它？
I am maintaining a legacy PHP system and can not close the connections those are established to execute the query.
我正在维护一个旧的 PHP 系统，无法关闭为执行查询而建立的连接。
Should I reduce the timeout values in my.cnf file those defaults to 8 hours?
我应该将 my.cnf 文件中的超时值减少到 8 小时吗？
# default 28800 seconds
interactive_timeout=60
wait_timeout=60
回答by Konerak
Manual cleanup:
手动清理：
You can KILL the processid.
你可以杀死进程ID。
mysql> show full processlist;
+---------+------------+-------------------+------+---------+-------+-------+-----------------------+
| Id | User | Host | db | Command | Time | State | Info |
+---------+------------+-------------------+------+---------+-------+-------+-----------------------+
| 1193777 | TestUser12 | 192.168.1.11:3775 | www | Sleep | 25946 | | NULL |
+---------+------------+-------------------+------+---------+-------+-------+-----------------------+
mysql> kill 1193777;
But:
但：
- the php application might report errors (or the webserver, check the error logs)
- don't fix what is not broken- if you're not short on connections, just leave them be.
- php 应用程序可能会报告错误（或网络服务器，检查错误日志）
- 不要修复没有损坏的东西- 如果你不缺少连接，就让它们保持原样。
Automatic cleaner service ;)
自动清洁服务;)
Or you configure your mysql-server by setting a shorter timeout on wait_timeoutand interactive_timeout
或者你通过设定一个较短的超时配置MySQL服务器wait_timeout和interactive_timeout
mysql> show variables like "%timeout%";
+--------------------------+-------+
| Variable_name | Value |
+--------------------------+-------+
| connect_timeout | 5 |
| delayed_insert_timeout | 300 |
| innodb_lock_wait_timeout | 50 |
| interactive_timeout | 28800 |
| net_read_timeout | 30 |
| net_write_timeout | 60 |
| slave_net_timeout | 3600 |
| table_lock_wait_timeout | 50 |
| wait_timeout | 28800 |
+--------------------------+-------+
9 rows in set (0.00 sec)
Set with:
设置：
set global wait_timeout=3;
set global interactive_timeout=3;
(and also set in your configuration file, for when your server restarts)
（也在你的配置文件中设置，当你的服务器重新启动时）
But you're treating the symptoms instead of the underlying cause - why are the connections open? If the PHP script finished, shouldn't they close? Make sure your webserver is not using connection pooling...
但是你是在治疗症状而不是根本原因——为什么这些联系是开放的？如果 PHP 脚本完成，它们不应该关闭吗？确保您的网络服务器没有使用连接池...
回答by guykaplan
I don't see any problem, unless you are not managing them using a connection pool.
我没有看到任何问题，除非您没有使用连接池管理它们。
If you use connection pool, these connections are re-used instead of initiating new connections. so basically, leaving open connections and re-use them it is less problematic than re-creating them each time.
如果使用连接池，这些连接将被重用，而不是启动新连接。所以基本上，留下打开的连接并重新使用它们比每次重新创建它们的问题要少。
