SELECT * FROM pg_stat_activity WHERE pid <> pg_backend_pid() ORDER BY backend_start;

<provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
<non-jta-data-source>java:comp/env/jdbc/source</non-jta-data-source>
<properties>
    <property name="hibernate.id.new_generator_mappings" value="true"/>
    <property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQL94Dialect"/>
    <property name="hibernate.connection.release_mode" value="on_close"/>
</properties>

<Resource auth="Container"
       driverClassName="org.postgresql.Driver"
       maxActive="20"
       maxIdle="10"
       maxWait="-1"
       name="jdbc/source"
       type="javax.sql.DataSource"
       username="postgres" password="postgres"
       url="jdbc:postgresql://localhost:5432/source"
       removeAbandoned="true"
       removeAbandonedTimeout="3"
       defaultAutoCommit="true"/>

@ManagedBean
@SessionScoped
public class Bean implements Serializable {

    private EntityManager emRepo;

    @PreDestroy
        public void cleanUp() {

            emRepo.close();
    }
}