C3P0 Configurations! Where and How?

Question

We are implementing a Web App using JPA2.0 and Hibernate3.0. Connection pool configurations are set in persistence.xml located in META-INF folder.

persistence.xml:

<persistence xmlns="http://java.sun.com/xml/ns/persistence" version="2.0">
    <persistence-unit name="MyPU" transaction-type="RESOURCE_LOCAL">
        <!-- Entity Classes-->
        <properties>
            <property name="hibernate.connection.driver_class" value="com.mysql.jdbc.Driver"/>
            <property name="hibernate.dialect" value="org.hibernate.dialect.MySQL5InnoDBDialect"/>
            <property name="hibernate.show_sql" value="true"/>
            <property name="bytecode.provider"   value="org.hibernate.bytecode.javassist.BytecodeProviderImpl"/>
            <property name="hibernate.connection.username" value="{username}"/>
            <property name="hibernate.connection.password" value="{password}"/>
            <property name="hibernate.hbm2ddl.auto" value="update"/>
            <property name="hibernate.format_sql" value="true"/>
            <property name="hibernate.connection.url" value="{jdbc url}"/>

            <property name="hibernate.c3p0.min_size" value="1"/>
            <property name="hibernate.c3p0.timeout" value="1000"/>
            <property name="hibernate.c3p0.acquire_increment" value="1"/>
            <property name="hibernate.c3p0.idle_test_periods" value="600"/>
            <property name="hibernate.c3p0.testConnectionOnCheckin" value="true"/>
            <property name="hibernate.c3p0.preferredTestQuery" value="SELECT 1;"/>
       </properties>
    </persistence-unit>
</persistence>

We have a problem with connection pool configurations. It seems the configurations have no effect and the connection will be broken after 8 hours. Do we need another configuration file like hibernate.cfg.xml or hibernate.properties?

Possible duplicate of [Best configuration of c3p0](https://stackoverflow.com/questions/12507021/best-configuration-of-c3p0) — Félix Adriyel Gagnon-Grenier, May 18 '19 at 03:24

score 4 · Answer 1 · answered Feb 27 '13 at 11:44

I had this same problem with the proprieties that I put in persistence.xml didn't affect c3p0.

Looking into http://www.mchange.com/projects/c3p0/index.html#configuration_files I tried to put an xml file named c3p0-config.xml and put it in WEB-INF/classes and it work perfectly.

Here is an example of a c3p0-config.xml file:

<c3p0-config>
  <default-config>
    <property name="automaticTestTable">con_test</property>
    <property name="checkoutTimeout">30000</property>
    <property name="idleConnectionTestPeriod">30</property>
    <property name="initialPoolSize">10</property>
    <property name="maxIdleTime">30</property>
    <property name="maxPoolSize">100</property>
    <property name="minPoolSize">10</property>
    <property name="maxStatements">200</property>

    <user-overrides user="test-user">
      <property name="maxPoolSize">10</property>
      <property name="minPoolSize">1</property>
      <property name="maxStatements">0</property>
    </user-overrides>

  </default-config>
</c3p0-config>

Philipi Willemann is right, if you add the c3p0 config xml, the properties will be read correctly. N.B. if you add some configuration properties which are already described in the hibernate.config file, hibernate will ignore them. For reference you can find more information here http://www.mchange.com/projects/c3p0/index.html#configuration_files under "Overriding c3p0 defaults via c3p0-config.xml" section — sataniccrow, Mar 14 '14 at 11:35

score 3 · Answer 2 · edited May 23 '17 at 12:25

3

Good question, bad title. :) I think I answered this question on your re-post: Best configuration of c3p0

edited May 23 '17 at 12:25

Community

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answered Sep 21 '12 at 13:23

Domenic D.

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The Gilbert Arenas Dagger · Answer 3 · 2014-09-10T14:50:14.173

1

I had the same exact issue, my problem was that my web application container (Tomcat) was managing my database connections. I had to move the c3p0 configuration from my persistence.xml file to Tomcat's context.xml. The link Domenic D provided is a great place to start if that's your problem.

edited Sep 10 '14 at 14:50

answered Sep 09 '14 at 14:40

The Gilbert Arenas Dagger

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score 1 · Answer 4 · edited Mar 14 '18 at 12:03

1

There is a typo in your settings, it should be idle_test_period not idle_test_periods.

See this post for information about the setting: The use of c3p0.idle_test_period.

edited Mar 14 '18 at 12:03

Turophile

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answered Mar 14 '18 at 11:12

Guest

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C3P0 Configurations! Where and How?

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