Re: [logback-user] DBAppender and EJB managed transactions

3 Feb 2012

      I made a work around which is in fact working, but I'm not quite happy with it:
I created a new Class DBAppender2 extending DBAppender and using the
javax.transaction.UserTransaction where
logback DBAppender used the transaction from the java.sql.Connection.
I then created an EJB with BMT(bean managed transaction, see
Annotation TransactionManagement).
In this Bean I added some logging methods like debug(String msg) and
so on. Those methods use Logger.debug and the like.
I'm now injecting this EJB in my other EJBs, so I can log via
'LoggingEJB' which has its own transaction management.

Some Code Snippets below:
public class DBAppender2 extends DBAppender {
	private String jndiLocationTransactor;

	/* (non-Javadoc)
	 * @see ch.qos.logback.core.db.DBAppenderBase#append(java.lang.Object)
	 */
	@Override
	public void append(ILoggingEvent eventObject) {
		Connection connection = null;
		try {
			connection = connectionSource.getConnection();
//			connection.setAutoCommit(false);
			Context context = new InitialContext();
			UserTransaction utx = (UserTransaction)
context.lookup(jndiLocationTransactor);
			utx.begin();
			// do something
//			connection.commit();
			utx.commit();
		} catch (Throwable sqle) {
			addError("problem appending event", sqle);
		} finally {
			DBHelper.closeConnection(connection);
		}
	}

	public String getJndiLocationTransactor() {
		return jndiLocationTransactor;
	}

	public void setJndiLocationTransactor(String jndiLocationTransactor) {
		this.jndiLocationTransactor = jndiLocationTransactor;
	}
}

config in logback.xml:
	<appender name="DBAppender2" class="ch.qos.logback.classic.db.DBAppender2">
		<filter class="ch.qos.logback.classic.filter.ThresholdFilter">
			<level>ALL</level>
		</filter>
		<connectionSource class="ch.qos.logback.core.db.JNDIConnectionSource">
			<param name="jndiLocation" value="java:/jndiToConnection" />
		</connectionSource>
		<jndiLocationTransactor>java:/jndiToUserTransaction</jndiLocationTransactor>
	</appender>

Logging-EJB:
@Stateless
@TransactionManagement(TransactionManagementType.BEAN)
public abstract class LoggingBean {

	private final Logger logger = LoggerFactory.getLogger(getClass());

	public void debug(String msg) {
		logger.debug(msg);
	}
}

call from another EJB:
@EJB LoggingBean loggerBean;
loggerBean.debug("Test");

Hope this help others having the same problems.

2012/1/31 Henning Diederichs <grave1740@googlemail.com>:
...
Hi there,
I think I found out, why I couldn't log in database as I described in December.
I activated the status listener as mentioned in an earlier question
concerning DBAppender like this:
<statusListener class="ch.qos.logback.core.status.OnConsoleStatusListener" />
and got this exception from JBoss:
ERROR in ch.qos.logback.classic.db.DBAppender[myDBAppender] - problem
appending event java.sql.SQLException: You cannot set autocommit
during a managed transaction!
       at java.sql.SQLException: You cannot set autocommit during a managed
transaction!
       at      at org.jboss.jca.adapters.jdbc.BaseWrapperManagedConnection.setJdbcAutoCommit(BaseWrapperManagedConnection.java:878)
       at      at org.jboss.jca.adapters.jdbc.WrappedConnection.setAutoCommit(WrappedConnection.java:712)
       at      at ch.qos.logback.core.db.DBAppenderBase.append(DBAppenderBase.java:90)
       at      at ch.qos.logback.core.UnsynchronizedAppenderBase.doAppend(UnsynchronizedAppenderBase.java:88)
       at      at ch.qos.logback.core.spi.AppenderAttachableImpl.appendLoopOnAppenders(AppenderAttachableImpl.java:64)
       at      at ch.qos.logback.classic.Logger.appendLoopOnAppenders(Logger.java:285)
       at      at ch.qos.logback.classic.Logger.callAppenders(Logger.java:272)
       at      at ch.qos.logback.classic.Logger.buildLoggingEventAndAppend(Logger.java:473)
       at      at ch.qos.logback.classic.Logger.filterAndLog_0_Or3Plus(Logger.java:427)
       at      at ch.qos.logback.classic.Logger.error(Logger.java:574)
The transaction is handled by the EJB container and cannot be managed
by DBAppenderBase line 90.
I also tested the DBAppender in a web project that only uses Servlets
and no EJBs. I could manage to log with the same log file.
Is this a known issue? There has to be a possibility to log to DB
without managing the transaction. Best if logback itself finds out, if
managing transactions manually is allowed or not.
Regards,
Henning