MYSQL數據庫MySQL中interactive_timeout和wait_timeout的區別

作者：VEPHP 時間 2017-10-17

《MYSQL數據庫MySQL中interactive_timeout和wait_timeout的區別》要點：
本文介紹了MYSQL數據庫MySQL中interactive_timeout和wait_timeout的區別，希望對您有用。如果有疑問，可以聯系我們。

在用mysql客戶端對數據庫進行操作時,打開終端窗口,如果一段時間沒有操作,再次操作時,常常會報如下錯誤：MYSQL學習

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

這個報錯信息就意味著當前的連接已經斷開,需要重新建立連接.MYSQL學習

那么,連接的時長是如何確認的?MYSQL學習

其實,這個與interactive_timeout和wait_timeout的設置有關.MYSQL學習

首先,看看官方文檔對于這兩個參數的定義MYSQL學習

interactive_timeoutMYSQL學習

默認是28800,單位秒,即8個小時MYSQL學習

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學習

默認同樣是28800sMYSQL學習

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

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學習

根據上述定義,兩者的區別顯而易見MYSQL學習

1> interactive_timeout針對交互式連接,wait_timeout針對非交互式連接.所謂的交互式連接,即在mysql_real_connect()函數中使用了CLIENT_INTERACTIVE選項.MYSQL學習

說得直白一點,通過mysql客戶端連接數據庫是交互式連接,通過jdbc連接數據庫是非交互式連接.MYSQL學習

2> 在連接啟動的時候,根據連接的類型,來確認會話變量wait_timeout的值是繼承于全局變量wait_timeout,還是interactive_timeout.MYSQL學習

下面來測試一下,確認如下問題MYSQL學習

1. 控制連接最大空閑時長的是哪個參數.MYSQL學習

2. 會話變量wait_timeout的繼承問題MYSQL學習

Q1：控制連接最大空閑時長的是哪個參數MYSQL學習

A1：wait_timeoutMYSQL學習

驗證MYSQL學習

只修改wait_timeout參數MYSQL學習

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后再執行
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后再執行操作,連接已經斷開.MYSQL學習

只修改interactive_timeout參數MYSQL學習

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后執行
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：會話變量wait_timeout的繼承問題MYSQL學習

A2：如果是交互式連接,則繼承全局變量interactive_timeout的值,如果是非交互式連接,則繼承全局變量wait_timeout的值.MYSQL學習

驗證：MYSQL學習

只修改全局變量interactive_timeout的值
MYSQL學習

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)

開啟另外一個mysql客戶端,查看會話變量的值MYSQL學習

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)

發現,WAIT_TIMEOUT的值已經變為10了.MYSQL學習

但通過jdbc測試,wait_timeout的值依舊是28800MYSQL學習

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));
}
}
}

結果輸出如下：MYSQL學習

INTERACTIVE_TIMEOUT: 10
WAIT_TIMEOUT: 28800
MYSQL學習

只修改全局變量wait_timeout的值MYSQL學習

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)

開啟另外一個mysql客戶端,查看會話變量的值MYSQL學習

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的值依舊是28800.MYSQL學習

查看jdbc的結果MYSQL學習

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的結果MYSQL學習

INTERACTIVE_TIMEOUT: 28800
WAIT_TIMEOUT: 20

同時,新增了一段程序,等待20s后,再次執行查詢,報如下錯誤：MYSQL學習

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

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

總結MYSQL學習

1. 控制連接最大空閑時長的wait_timeout參數.MYSQL學習

2. 對于非交互式連接,類似于jdbc連接,wait_timeout的值繼承自服務器端全局變量wait_timeout.MYSQL學習

對于交互式連接,類似于mysql客戶單連接,wait_timeout的值繼承自服務器端全局變量interactive_timeout.MYSQL學習

3. 判斷一個連接的空閑時間,可通過show processlist輸出中Sleep狀態的時間MYSQL學習

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)

以上所述是小編給大家介紹的MySQL中interactive_timeout和wait_timeout的區別,希望對大家有所贊助,如果大家有任何疑問請給我留言,小編會及時回復大家的.在此也非常感謝大家對維易PHP網站的支持!MYSQL學習

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