Bug 165188 logging per report
Setting up a dedicated (birt) report server, which serves all our web apps, leads to a logging desaster. Birtegine logs all messages to one file. There's no info which rptdesign caused the logmessage or who (e.g. user) caused the logmessage. Retrieving who/which rpt caused some logmessage is not possible! There are two possible solutions: (a) prefixing each logmessage with a userdefineable message (task.setLogprefix("myprefix")) (b) set an outputstream for each task (task.setLoggingOutputStream(outputstream)) to split the huge logfile to many small pieces.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/api/impl/EngineTask.java
{
		ReportDesignHandle reportDesign = executionContext.getDesign( );
		ReportScriptExecutor.handleAfterRender( reportDesign, executionContext );
	}
	
	public void setDataSource( IDocArchiveReader dataSource )
	{
		
		try
		{
			ReportDocumentReader document = new ReportDocumentReader( engine,
					dataSource, true );
			Map values = document.getParameterValues( );
			Map texts = document.getParameterDisplayTexts( );
			setParameterValues( values );
			setParameterDisplayTexts( texts );
			document.close( );
		}
		catch ( EngineException ex )
		{
			log.log( Level.WARNING,
					"failed to load the paremters in the data source", ex );
		}
		try
		{
			executionContext.setDataSource( dataSource );
		}
		catch ( IOException ioex )
		{
			log.log( Level.WARNING, "failed to open the data source document",