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Connection pool

Alf Gomez

Joined: Sep 28, 2004
Posts: 3
Hi all,

I have a Struts/Hibernate/MySQL application that doesn�t work well when working intensive against the DB.

The problem, is that to get some result, we execute SELECT�s in a loop, and after a while it crashes.

The error displayed in Firefox is:
javax.servlet.ServletException: Cannot open connection

But in the log, appears:
[2008-01-25 12:51:00,494] - SQL Error: 0, SQLState: 08S01
[2008-01-25 12:51:00,494] - Communications link failure due to underlying exception:

MESSAGE: Address already in use: connect

STACKTRACE: Address already in use: connect

I have read that the cause is that we exceed the number of socket connections, because we don�t use a pool.

I have the following configuration:
<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost/ph"/>
<property name="username" value="ph"/>
<property name="password" value="Ckue412lo"/>

<!-- Database Property -->
<bean id="hibernateProperties" class="org.springframework.beans.factory.config.PropertiesFactoryBean">
<property name="properties">
<prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
<prop key="hibernate.query.substitutions">true 'T', false 'F'</prop>
<prop key="hibernate.show_sql">false</prop>

<prop key="hibernate.query.factory_class">org.hibernate.hql.classic.ClassicQueryTranslatorFactory</prop>


How can I configure a pool of connections?
It is integrated in the MySQL database, or I have to include some libraries?

Any help would be appreciated.
Roger Chung-Wee
Ranch Hand

Joined: Sep 29, 2002
Posts: 1683
There are several options for connection pooling.

I cannot comment on these options as I have never used any of them. All my development is server-side using WebLogic Server.

SCJP 1.4, SCWCD 1.3, SCBCD 1.3
Alf Gomez

Joined: Sep 28, 2004
Posts: 3
Thanks Roger
I agree. Here's the link:
subject: Connection pool
It's not a secret anymore!