当前位置: 首页 > 编程笔记 >

MySQL中interactive_timeout和wait_timeout的区别

邹宣
2023-03-14
本文向大家介绍MySQL中interactive_timeout和wait_timeout的区别,包括了MySQL中interactive_timeout和wait_timeout的区别的使用技巧和注意事项,需要的朋友参考一下

在用mysql客户端对数据库进行操作时,打开终端窗口,如果一段时间没有操作,再次操作时,常常会报如下错误:

ERROR 2013 (HY000): Lost connection to MySQL server during query
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...

这个报错信息就意味着当前的连接已经断开,需要重新建立连接。

那么,连接的时长是如何确认的?

其实,这个与interactive_timeout和wait_timeout的设置有关。

首先,看看官方文档对于这两个参数的定义

interactive_timeout

默认是28800,单位秒,即8个小时

The number of seconds the server waits for activity on an interactive connection before closing it. An interactive client is defined as a client that uses the CLIENT_INTERACTIVE option to mysql_real_connect(). See also wait_timeout.

wait_timeout

默认同样是28800s

The number of seconds the server waits for activity on a noninteractive connection before closing it.

On thread startup, the session wait_timeout value is initialized from the global wait_timeout value or from the global interactive_timeout value, depending on the type of client (as defined by the CLIENT_INTERACTIVE connect option to mysql_real_connect()). See also interactive_timeout.

根据上述定义,两者的区别显而易见

1> interactive_timeout针对交互式连接,wait_timeout针对非交互式连接。所谓的交互式连接,即在mysql_real_connect()函数中使用了CLIENT_INTERACTIVE选项。

说得直白一点,通过mysql客户端连接数据库是交互式连接,通过jdbc连接数据库是非交互式连接。

2> 在连接启动的时候,根据连接的类型,来确认会话变量wait_timeout的值是继承于全局变量wait_timeout,还是interactive_timeout。

下面来测试一下,确认如下问题

1. 控制连接最大空闲时长的是哪个参数。

2. 会话变量wait_timeout的继承问题

Q1:控制连接最大空闲时长的是哪个参数

A1:wait_timeout

验证

只修改wait_timeout参数

mysql> select variable_name,variable_value from information_schema.session_variables where variable_name in ('interactive_timeout','wait_timeout');
+---------------------+----------------+
| variable_name | variable_value |
+---------------------+----------------+
| INTERACTIVE_TIMEOUT | 28800 |
| WAIT_TIMEOUT | 28800 |
+---------------------+----------------+
2 rows in set (0.03 sec)

mysql> set session WAIT_TIMEOUT=10;
Query OK, 0 rows affected (0.00 sec)
-------等待10s后再执行
mysql> select variable_name,variable_value from information_schema.session_variables where variable_name in ('interactive_timeout','wait_timeout');
ERROR 2013 (HY000): Lost connection to MySQL server during query

可以看到,等待10s后再执行操作,连接已经断开。

只修改interactive_timeout参数

mysql> select variable_name,variable_value from information_schema.session_variables where variable_name in ('interactive_timeout','wait_timeout');
+---------------------+----------------+
| variable_name | variable_value |
+---------------------+----------------+
| INTERACTIVE_TIMEOUT | 28800 |
| WAIT_TIMEOUT | 28800 |
+---------------------+----------------+
2 rows in set (0.06 sec)
mysql> set session INTERACTIVE_TIMEOUT=10;
Query OK, 0 rows affected (0.00 sec)
----------等待10s后执行
mysql> select variable_name,variable_value from information_schema.session_variables where variable_name in ('interactive_timeout','wait_timeout');
+---------------------+----------------+
| variable_name | variable_value |
+---------------------+----------------+
| INTERACTIVE_TIMEOUT | 10 |
| WAIT_TIMEOUT | 28800 |
+---------------------+----------------+
2 rows in set (0.06 sec)

Q2:会话变量wait_timeout的继承问题

A2:如果是交互式连接,则继承全局变量interactive_timeout的值,如果是非交互式连接,则继承全局变量wait_timeout的值。

验证:

只修改全局变量interactive_timeout的值

mysql> select variable_name,variable_value from information_schema.global_variables where variable_name in ('interactive_timeout','wait_timeout'); 
+---------------------+----------------+
| variable_name | variable_value |
+---------------------+----------------+
| INTERACTIVE_TIMEOUT | 28800 |
| WAIT_TIMEOUT | 28800 |
+---------------------+----------------+
2 rows in set (0.13 sec)

mysql> set global INTERACTIVE_TIMEOUT=10;
Query OK, 0 rows affected (0.00 sec)
mysql> select variable_name,variable_value from information_schema.global_variables where variable_name in ('interactive_timeout','wait_timeout');
+---------------------+----------------+
| variable_name | variable_value |
+---------------------+----------------+
| INTERACTIVE_TIMEOUT | 10 |
| WAIT_TIMEOUT | 28800 |
+---------------------+----------------+
2 rows in set (0.00 sec)

开启另外一个mysql客户端,查看会话变量的值

mysql> select variable_name,variable_value from information_schema.session_variables where variable_name in ('interactive_timeout','wait_timeout');
+---------------------+----------------+
| variable_name | variable_value |
+---------------------+----------------+
| INTERACTIVE_TIMEOUT | 10 |
| WAIT_TIMEOUT | 10 |
+---------------------+----------------+
2 rows in set (0.00 sec)

发现,WAIT_TIMEOUT的值已经变为10了。

但通过jdbc测试,wait_timeout的值依旧是28800

public class Jdbc_test {
@SuppressWarnings("static-access")
public static void main(String[] args) throws Exception {
Connection conn = null;
Statement stmt = null;
ResultSet rs = null;
String url = "jdbc:mysql://192.168.244.10:3306/test";
String user = "root";
String password = "123456";
Class.forName("com.mysql.jdbc.Driver");
conn = DriverManager.getConnection(url, user, password);
stmt = conn.createStatement();
String sql = "select variable_name,variable_value from information_schema.session_variables where variable_name in ('interactive_timeout','wait_timeout')";
rs = stmt.executeQuery(sql);
while (rs.next()) {
System.out
.println(rs.getString(1)+": "+rs.getString(2));
}
}
}

结果输出如下:

INTERACTIVE_TIMEOUT: 10
WAIT_TIMEOUT: 28800

只修改全局变量wait_timeout的值

mysql> select variable_name,variable_value from information_schema.global_variables where variable_name in ('interactive_timeout','wa
it_timeout');+---------------------+----------------+
| variable_name | variable_value |
+---------------------+----------------+
| INTERACTIVE_TIMEOUT | 28800 |
| WAIT_TIMEOUT | 28800 |
+---------------------+----------------+
2 rows in set (0.17 sec)
mysql> set global WAIT_TIMEOUT=20;
Query OK, 0 rows affected (0.07 sec)
mysql> select variable_name,variable_value from information_schema.global_variables where variable_name in ('interactive_timeout','wa
it_timeout');+---------------------+----------------+
| variable_name | variable_value |
+---------------------+----------------+
| INTERACTIVE_TIMEOUT | 28800 |
| WAIT_TIMEOUT | 20 |
+---------------------+----------------+
2 rows in set (0.00 sec)

开启另外一个mysql客户端,查看会话变量的值

mysql> select variable_name,variable_value from information_schema.session_variables where variable_name in ('interactive_timeout','wait_timeout');
+---------------------+----------------+
| variable_name | variable_value |
+---------------------+----------------+
| INTERACTIVE_TIMEOUT | 28800 |
| WAIT_TIMEOUT | 28800 |
+---------------------+----------------+
2 rows in set (0.03 sec)

WAIT_TIMEOUT的值依旧是28800.

查看jdbc的结果

public class Jdbc_test {
@SuppressWarnings("static-access")
public static void main(String[] args) throws Exception {
Connection conn = null;
Statement stmt = null;
ResultSet rs = null;
String url = "jdbc:mysql://192.168.244.10:3306/test";
String user = "root";
String password = "123456";
Class.forName("com.mysql.jdbc.Driver");
conn = DriverManager.getConnection(url, user, password);
stmt = conn.createStatement();
String sql = "select variable_name,variable_value from information_schema.session_variables where variable_name in ('interactive_timeout','wait_timeout')";
rs = stmt.executeQuery(sql);
while (rs.next()) {
System.out
.println(rs.getString(1)+": "+rs.getString(2));
}
Thread.currentThread().sleep(21000);
sql = "select 1 from dual";
rs = stmt.executeQuery(sql);
while (rs.next()) {
System.out
.println(rs.getInt(1));
}
}
}

查看jdbc的结果

INTERACTIVE_TIMEOUT: 28800
WAIT_TIMEOUT: 20

同时,新增了一段程序,等待20s后,再次执行查询,报如下错误:

Exception in thread "main" com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

Last packet sent to the server was 12 ms ago.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1074)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3009)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2895)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3438)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1951)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2101)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2548)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2477)
at com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1422)
at com.victor_01.Jdbc_test.main(Jdbc_test.java:29)
Caused by: java.net.SocketException: Software caused connection abort: recv failed
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.socketRead(Unknown Source)
at java.net.SocketInputStream.read(Unknown Source)
at java.net.SocketInputStream.read(Unknown Source)
at com.mysql.jdbc.util.ReadAheadInputStream.fill(ReadAheadInputStream.java:113)
at com.mysql.jdbc.util.ReadAheadInputStream.readFromUnderlyingStreamIfNecessary(ReadAheadInputStream.java:160)
at com.mysql.jdbc.util.ReadAheadInputStream.read(ReadAheadInputStream.java:188)
at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:2452)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2906)
... 8 more

总结

1. 控制连接最大空闲时长的wait_timeout参数。

2. 对于非交互式连接,类似于jdbc连接,wait_timeout的值继承自服务器端全局变量wait_timeout。

对于交互式连接,类似于mysql客户单连接,wait_timeout的值继承自服务器端全局变量interactive_timeout。

3. 判断一个连接的空闲时间,可通过show processlist输出中Sleep状态的时间

mysql> show processlist;
+----+------+----------------------+------+---------+------+-------+------------------+
| Id | User | Host | db | Command | Time | State | Info |
+----+------+----------------------+------+---------+------+-------+------------------+
| 2 | root | localhost | NULL | Query | 0 | init | show processlist |
| 6 | repl | 192.168.244.20:44641 | NULL | Sleep | 1154 | | NULL |
+----+------+----------------------+------+---------+------+-------+------------------+
2 rows in set (0.03 sec)

以上所述是小编给大家介绍的MySQL中interactive_timeout和wait_timeout的区别,希望对大家有所帮助,如果大家有任何疑问请给我留言,小编会及时回复大家的。在此也非常感谢大家对小牛知识库网站的支持!

 类似资料:
  • 问题内容: 之间有什么区别 和 问题答案: 可以执行通配符匹配: 如果不需要模式匹配,请使用=代替LIKE。它更快,更安全。(您正在使用参数化查询,对吗?)

  • 问题内容: 这个问题已经在这里有了答案 : MySQL中的VARCHAR vs TEXT (3个答案) 3个月前关闭。 当我们在MySQL中创建带有列的表时,我们必须为其设置长度。但是对于类型,我们不必提供长度。 和之间有什么区别? 问题答案: TL; DR 固定的最大大小为65535个字符(您不能限制最大大小) 占用2 + 字节的磁盘空间,其中是存储的字符串的长度。 不能(完全)成为索引的一部分

  • 问题内容: 似乎和我做同样的事情。 在任何情况下我都应该使用代替,反之亦然? 问题答案: 在CRUD操作中,“ 是”和“ U”。它们是持久性存储的四个基本功能中的两个。另外两个是和。如果没有至少这四个操作,则不能认为典型的数据库系统是完整的。 使用插入一个新的记录。 使用更新现有的记录。

  • 问题内容: 在哪种情况下,您会使用哪种?有什么区别吗?持久性引擎通常使用哪一个来存储布尔值? 问题答案: TINYINT是8位整数值,BIT字段可以存储1位BIT(1)和64位BIT(64)之间。对于布尔值,BIT(1)很常见。

  • 本文向大家介绍mysql分表和分区的区别浅析,包括了mysql分表和分区的区别浅析的使用技巧和注意事项,需要的朋友参考一下 数据库的数据量达到一定程度之后,为避免带来系统性能上的瓶颈。需要进行数据的处理,采用的手段是分区、分片、分库、分表。 一、什么是mysql分表和分区 什么是分表,从表面意思上看呢,就是把一张表分成N多个小表 什么是分区,分区呢就是把一张表的数据分成N多个区块,这些区块可以在同

  • 本文向大家介绍MySQL和MongoDB之间的区别,包括了MySQL和MongoDB之间的区别的使用技巧和注意事项,需要的朋友参考一下 MySQL是一个关系数据库。MongoDB是NoSQL数据库。 以下是MySQL和MongoDB之间的重要区别。 序号 键 的MySQL MongoDB 1 拥有/开发 MySQL由Oracle拥有。 MongoDB由MongoDB Inc.开发。 2 数据存储