c3p0's max number of connections doesn't work in Linux

I have a java application that uses hibernate for O/R mapping and I also use c3p0 connection pooling that ships together with hibernate. The DB is Oracle.

This is in my hibernate.cfg.xml:

<property name="hibernate.c3p0.min_size">3</property>
<property name="hibernate.c3p0.max_size">5</property>
<property name="hibernate.c3p0.max_statements">20</property>
<property name="hibernate.c3p0.timeout">1800</property>
<property name="hibernate.c3p0.idleTestPeriod">120</property>        

This is how I obtain the hibernate session:

public class HibernateUtil {
    private static Logger log = Logger.getLogger(HibernateUtil.class);
    private static final SessionFactory sessionFactory;

    private static String CONFIG_FILE_LOCATION = "/hibernate.cfg.xml";
    static {
        try {
            // Create the SessionFactory from hibernate.cfg.xml
            sessionFactory = new Configuration().configure(CONFIG_FILE_LOCATION).buildSessionFactory();
        } catch (Throwable ex) {
            // Make sure you log the exception, as it might be swallowed
            log.fatal("Initial SessionFactory开发者_StackOverflow中文版 creation failed." + ex.getMessage());
            throw new ExceptionInInitializerError(ex);
        }
    }

    public static SessionFactory getSessionFactory() {
        return sessionFactory;
    }
}

But when I run SELECT * FROM V$SESSION WHERE machine='xxx'; in Oracle the number of connections can reach 20, which is greater than max_size.

The max connections don't work in Linux environment but they do in Unix and Windows. Any setting in Linux that needs to be tweaked?

I'm also suspecting there is a cache of the application somewhere, as previously I set max_size of 20. I'm running the application in Tomcat 5.5. But I don't know of such an application cache in Tomcat.

Another info: I'm running Linux 2.6.9-34.ELsmp. Red Hat Enterprise Linux AS release 4 (Nahant Update 3)

Thanks.

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I'd guess you have additional DB sessions opened not from your application. For example, there should be an additional connection - the one you're using to run the SELECT statement.