如何在启动时预初始化DBCP连接池？ [英] How to preinitialize DBCP connection pool on startup?

问题描述

我的项目设置是 -

The setup of my project is -

1. Spring JDBC for persistence


2. Apache DBCP 1.4用于连接池


3. Linux上的Mysql 5

这是我的应用程序捕获的日志与数据库的交互。

Here is the log of my application that captures the interactions with the database.

2013-01-29 15:52:21,549 DEBUG http-bio-8080-exec-3 org.springframework.jdbc.core.JdbcTemplate - Executing SQL query [SELECT id from emp]
2013-01-29 15:52:21,558 DEBUG http-bio-8080-exec-3 org.springframework.jdbc.datasource.DataSourceUtils - Fetching JDBC Connection from DataSource
2013-01-29 15:52:31,878  INFO http-bio-8080-exec-3 jdbc.connection - 1. Connection opened  org.apache.commons.dbcp.DriverConnectionFactory.createConnection(DriverConnectionFactory.java:38)
2013-01-29 15:52:31,878 DEBUG http-bio-8080-exec-3 jdbc.connection - open connections:  1 (1)
2013-01-29 15:52:31,895  INFO http-bio-8080-exec-3 jdbc.connection - 1. Connection closed  org.apache.commons.dbcp.DelegatingConnection.close(DelegatingConnection.java:247)
2013-01-29 15:52:31,895 DEBUG http-bio-8080-exec-3 jdbc.connection - open connections:  none
2013-01-29 15:52:41,950  INFO http-bio-8080-exec-3 jdbc.connection - 2. Connection opened  org.apache.commons.dbcp.DriverConnectionFactory.createConnection(DriverConnectionFactory.java:38)
2013-01-29 15:52:41,950 DEBUG http-bio-8080-exec-3 jdbc.connection - open connections:  2 (1)
2013-01-29 15:52:52,001  INFO http-bio-8080-exec-3 jdbc.connection - 3. Connection opened  org.apache.commons.dbcp.DriverConnectionFactory.createConnection(DriverConnectionFactory.java:38)
2013-01-29 15:52:52,002 DEBUG http-bio-8080-exec-3 jdbc.connection - open connections:  2 3 (2)
2013-01-29 15:53:02,058  INFO http-bio-8080-exec-3 jdbc.connection - 4. Connection opened  org.apache.commons.dbcp.DriverConnectionFactory.createConnection(DriverConnectionFactory.java:38)
2013-01-29 15:53:02,058 DEBUG http-bio-8080-exec-3 jdbc.connection - open connections:  2 3 4 (3)
2013-01-29 15:53:03,403 DEBUG http-bio-8080-exec-3 org.springframework.jdbc.core.BeanPropertyRowMapper - Mapping column 'id' to property 'id' of type int
2013-01-29 15:53:04,494 DEBUG http-bio-8080-exec-3 org.springframework.jdbc.datasource.DataSourceUtils - Returning JDBC Connection to DataSource

日志中有两件事情是清楚的 -

Two things are clear from the log -

1. 当收到第一个执行查询的请求时，连接池才开始创建连接。


2. 4个连接的池接近30个初始化的秒数。

我的问题是 -

1. 应该如何配置DBCP在启动时自动初始化？


2. 创建连接真的需要很长时间吗？

1. How should one configure DBCP to initialize on startup automatically?
2. Should it really take that long to create connections?

注意：请不要建议切换到C3P0或Tomca连接池。我知道那些解决方案。我更感兴趣的是了解手头的问题，而不仅仅是快速修复。
此外我确信DBCP也可以这么基本。

dbcontext的内容 -

Contents of dbcontext -

<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
    <property name="driverClassName" value="${db.driver}" />
    <property name="url" value="${db.jdbc.url}" />
    <property name="username" value="${db.user}" />
    <property name="password" value="${db.password}" />
    <property name="maxActive" value="20" />
    <property name="initialSize" value="4" />
    <property name="testOnBorrow" value="true" />
    <property name="validationQuery" value="SELECT 1" />
</bean>

推荐答案

在您第一次请求之前，initialSize不会生效一个连接。从java文档到 BasicDataSource #setInitialSize

The initialSize doesn't take effect until you first request a connection. From the java docs to BasicDataSource#setInitialSize

设置连接池的初始大小。

Sets the initial size of the connection pool.

注意：一旦池初始化为
，此方法当前无效。第一次调用
以下方法之一时初始化池：getConnection，setLogwriter，
setLoginTimeout，getLoginTimeout，getLogWriter。

Note: this method currently has no effect once the pool has been initialized. The pool is initialized the first time one of the following methods is invoked: getConnection, setLogwriter, setLoginTimeout, getLoginTimeout, getLogWriter.

尝试将 init-method =getLoginTimeout添加到您的bean中以确认这一点。

Try adding init-method="getLoginTimeout" to your bean to confirm this.

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