Tomcat的不關閉連接，仍然在睡眠模式下

Question

我們使用Tomcat 6.0.26與MySQL 5.1，如下面給出的，以數據庫的連接是建立在server.xml中，

<GlobalNamingResources> 
<!-- Editable user database that can also be used by 
    UserDatabaseRealm to authenticate users 
--> 
<Resource name="UserDatabase" auth="Container" 
      type="org.apache.catalina.UserDatabase" 
      description="User database that can be updated and saved" 
      factory="org.apache.catalina.users.MemoryUserDatabaseFactory" 
      pathname="conf/tomcat-users.xml" /> 

<Resource name="jdbc/abs" type="javax.sql.DataSource" maxActive="150" maxIdle="5" username="XXXXXXXXXXX" testWhileIdle="true" removeAbandonedTimeout="60" maxWait="-1" removeAbandoned="true" 
    validationQuery="select 1" driverClassName="com.mysql.jdbc.Driver" password="XXXXXXXXXXX" minEvictableIdleTimeMillis="30000" timeBetweenEvictionRunsMillis="300000" url="jdbc:mysql://XXXXXXXXXXXX?autoReconnect=true&amp;useUnicode=true&amp;characterEncoding=utf-8"/> 

    <Resource driverClassName="com.mysql.jdbc.Driver" maxActive="150" maxIdle="5" maxWait="-1" testWhileIdle="true" minEvictableIdleTimeMillis="30000" removeAbandonedTimeout="60" timeBetweenEvictionRunsMillis="300000" name="jdbc/1234" password="XXXXXXXXXXX" removeAbandoned="true" type="javax.sql.DataSource" url="jdbc:mysql:///XXXXXXXXXXXXXXXXXXXXXX?autoReconnect=true&amp;useUnicode=true&amp;characterEncoding=utf-8" username="XXXXXXXXXXX" validationQuery="select 1"/> 

當我在MySql中運行show full processlist，它顯示很多連接仍處於睡眠模式，可能會導致這種情況？

問候，

羅希特

Answer 1

一個javax.sql.DataSource是一個連接池到MySQL。您的應用程序服務器將打開一些連接到MySQL（保持休眠模式），並在每次執行時使用它們：

DataSource ds = ...; 
// you get one of the 'sleeping' connections here 
Connection conn = ds.getConnection(); 
// you return the connection to the pool here (it does not actually closes it) 
conn.close();