MYSQL数据库MySQL中interactive_timeout和wait_timeout的区别

作者：VEPHP 时间 2017-10-17

《MYSQL数据库MySQL中interactive_timeout和wait_timeout的区别》要点：
本文介绍了MYSQL数据库MySQL中interactive_timeout和wait_timeout的区别，希望对您有用。如果有疑问，可以联系我们。

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：MYSQL学习

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.MYSQL学习

那么,连接的时长是如何确认的?MYSQL学习

其实,这个与interactive_timeout和wait_timeout的设置有关.MYSQL学习

首先,看看官方文档对于这两个参数的定义MYSQL学习

interactive_timeoutMYSQL学习

默认是28800,单位秒,即8个小时MYSQL学习

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_timeoutMYSQL学习

默认同样是28800sMYSQL学习

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

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.
MYSQL学习

根据上述定义,两者的区别显而易见MYSQL学习

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.MYSQL学习

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.MYSQL学习

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.MYSQL学习

下面来测试一下,确认如下问题MYSQL学习

1. 控制连接最大空闲时长的是哪个参数.MYSQL学习

2. 会话变量wait_timeout的继承问题MYSQL学习

Q1：控制连接最大空闲时长的是哪个参数MYSQL学习

A1：wait_timeoutMYSQL学习

验证MYSQL学习

只修改wait_timeout参数MYSQL学习

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.MYSQL学习

只修改interactive_timeout参数MYSQL学习

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MYSQL学习

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.MYSQL学习

验证：MYSQL学习

只修改全局变量interactive_timeout的值
MYSQL学习

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学习

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.MYSQL学习

但通过jdbc测试,wait_timeout的值依旧是28800MYSQL学习

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：MYSQL学习

INTERACTIVE_TIMEOUT: 10
WAIT_TIMEOUT: 28800
MYSQL学习

只修改全局变量wait_timeout的值MYSQL学习

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学习

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.MYSQL学习

查看jdbc的结果MYSQL学习

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MYSQL学习

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：MYSQL学习

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

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MYSQL学习

1. 控制连接最大空闲时长的wait_timeout参数.MYSQL学习

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.MYSQL学习

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.MYSQL学习

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学习

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,希望对大家有所赞助,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维易PHP网站的支持!MYSQL学习

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