Tomcat에서 DBCP 사용할 때 Memory leak

Problem Domain

registered the JDBC driver [com.mysql.jdbc.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.

 - dbcp, boneCP를 사용하던... 에러는 발생한다.

 - mySQL, Oracle 관계 없이 에러는 발생한다.

 - JPA(+ Hibernate)를 사용할 때만 에러가 발생한다. (JPA를 사용하지 않을 때는 에러가 발생하지 않는다.)

    : org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean 및 관련 클래스를 등록하여

      사용할 경우 (나만그런가?)

Solve

해결 방법... google.com과 stackoverflow.com에서 방황을...-_-;;

1. DataSource가 Close 되는 시점에 명시적으로 드라이버를 unregister 시켜준다.

- extended BasicDataSource class

public class DisposableBasicDataSource extends BasicDataSource {  @Override public synchronized void close() throws SQLException { DriverManager.deregisterDriver(DriverManager.getDriver(url)); super.close(); } }

- added listener

public class JdbcDriverRegistrationListener implements ServletContextListener {     /**      * Default constructor.       */     public JdbcDriverRegistrationListener() {         // TODO Auto-generated constructor stub     } /**      * @see ServletContextListener#contextDestroyed(ServletContextEvent)      */     public void contextDestroyed(ServletContextEvent sce)  {     /**     * simple     */     /*     Enumeration<Driver> drivers = DriverManager.getDrivers();         while (drivers.hasMoreElements()) {             Driver driver = drivers.nextElement();             try {                 DriverManager.deregisterDriver(driver);                 log.info(String.format("deregistering jdbc driver: %s", driver));             } catch (SQLException e) {             log.info(String.format("Error deregistering driver %s", driver), e);             }         }         */         // ... First close any background tasks which may be using the DB ...         // ... Then close any DB connection pools ...         // Now deregister JDBC drivers in this context's ClassLoader:         // Get the webapp's ClassLoader         ClassLoader cl = Thread.currentThread().getContextClassLoader();         // Loop through all drivers         Enumeration<Driver> drivers = DriverManager.getDrivers();         while (drivers.hasMoreElements()) {             Driver driver = drivers.nextElement();             if (driver.getClass().getClassLoader() == cl) {                 // This driver was registered by the webapp's ClassLoader, so deregister it:                 try {                     log.info("Deregistering JDBC driver {}", driver);                     DriverManager.deregisterDriver(driver);                 } catch (SQLException ex) {                     log.error("Error deregistering JDBC driver {}", driver, ex);                 }             } else {                 // driver was not registered by the webapp's ClassLoader and may be in use elsewhere                 log.trace("Not deregistering JDBC driver {} as it does not belong to this webapp's ClassLoader", driver);             }         }     }      /**      * @see ServletContextListener#contextInitialized(ServletContextEvent)      */     public void contextInitialized(ServletContextEvent sce)  {           // TODO Auto-generated method stub     } }

2. 톰켓 lib 폴더에 jdbc 드라이버 jar를 복사한다.

3. JNDI를 사용한다.

컨테이너 리로드가 필요없는 서버는 상관없음.

톰켓에서만 나는건지 아니면 다른 WAS도 그런건지 잘 모르겠음.