Question

We are using a j2ee application with spring framework 2.0. The server used is tomcat 5.5. The database used is mysql. We are using a VPS for hosting our application and we have noticed that the CPU usage increases with more users using our application. The CPU usage does not come down once the users stop using the application. Is it the connections that are not closed properly or is there any other issue?

Here is the servlet.xml configuration for the connections

<bean id="myDataSource" class="org.apache.commons.dbcp.BasicDataSource">
      <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
    <property name="url" value="jdbc:mysql://localhost/myDB"/>
    <property name="username" value="xxxx"/>
    <property name="password" value="xxxx"/>
    <property name="validationQuery" value="SELECT 1"/>
      <property name="testOnBorrow" value="true"/>
    </bean>

We have also tried using

<bean id="myDataSource"
       class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
    <property name="url" value="jdbc:mysql://localhost/myDB"/>
    <property name="username" value="xxxx"/>
    <property name="password" value="xxxx"/>
 </bean>

But both of them cause the same problem. Can anyone help us out quickly? Because we need to correct this issue at the earliest. Thanks in advance.

Answer 1

It is unlikely that high CPU usage be caused by some connection pool issues. It’s probably a mistake within your application code. Did you monitored database connections — are they released and closed properly?

By the way, I’d suggest you switch to the native connection pool built in Tomcat. It can be obtained as a standard Java EE resource from the pseudo-JNDI implemented in Tomcat.