Hello, I would like to simplify stacktraces when errors occur in an application. For example, with a hypothetical stack such as: com.xyz.Wombat.doSomething javax.servlet.http.HttpServlet.service org.appserver.JspCompiler.handleJsp org.appserver.ServletEngine.handleServlet java.lang.Thread.run ...going down from top-to-bottom, I'd like to detect that line "org.appserver.JspCompiler.handleJsp" has been found, and exclude it -- and all subsequent "lower down" stack frames -- from logging output. Looking at http://logback.qos.ch/manual/layouts.html#Evaluators I assume it must be possible with EventEvaluator because of the syntax %xEx{evaluator-n} but I can't find an example. Furthermore, as I set up LogBack programmatically (and not via XML or any of bundled "configurator"), I'd be happiest if I could be directed towards an API-based example. If it's of any use, here are two methods extracted from the class that I use to configure LogBack (incomplete but should help see what I'm trying to do, and how): private synchronized boolean maybeInitialize(final Logger logger, String pattern) { // will throw ClassCastException if our configuration is incorrect (or accessed from wrong classloader) // that's OK, it's what should happen... final ch.qos.logback.classic.Logger impl = (ch.qos.logback.classic.Logger)logger; // if there's an appender, then the logger seems to have been configured Iterator<Appender<ILoggingEvent>> it = impl.iteratorForAppenders(); if (it.hasNext()) { return false; } String logFileName = impl.getName(); if (logFileName.startsWith(LOG_FILE_STDPREFIX) && logFileName.length() > LOG_FILE_STDPREFIX.length()) { logFileName = logFileName.substring(LOG_FILE_STDPREFIX.length()); } logFileName += LOG_FILE_EXTENSION; Appender<ILoggingEvent> appender; if (CONFIG_VALUE_ROLL_TYPE_DATE.equals(_rollType)) { appender = createRollByDateFileAppender(logFileName, pattern != null ? pattern : PATTERN_FOR_DATE); } else if (CONFIG_VALUE_ROLL_TYPE_SIZE.equals(_rollType)) { appender = createRollBySizeFileAppender(logFileName, pattern); } else { appender = createFileAppender(logFileName, pattern); } appender.start(); impl.addAppender(appender); impl.setLevel(_level); impl.setAdditive(false); return true; } private synchronized boolean maybeInitialize(final Logger logger, String pattern) { // will throw ClassCastException if our configuration is incorrect (or accessed from wrong classloader) // that's OK, it's what should happen... final ch.qos.logback.classic.Logger impl = (ch.qos.logback.classic.Logger)logger; // if there's an appender, then the logger seems to have been configured Iterator<Appender<ILoggingEvent>> it = impl.iteratorForAppenders(); if (it.hasNext()) { return false; } String logFileName = impl.getName(); if (logFileName.startsWith(LOG_FILE_STDPREFIX) && logFileName.length() > LOG_FILE_STDPREFIX.length()) { logFileName = logFileName.substring(LOG_FILE_STDPREFIX.length()); } logFileName += LOG_FILE_EXTENSION; Appender<ILoggingEvent> appender; if (CONFIG_VALUE_ROLL_TYPE_DATE.equals(_rollType)) { appender = createRollByDateFileAppender(logFileName, pattern != null ? pattern : PATTERN_FOR_DATE); } else if (CONFIG_VALUE_ROLL_TYPE_SIZE.equals(_rollType)) { appender = createRollBySizeFileAppender(logFileName, pattern); } else { appender = createFileAppender(logFileName, pattern); } appender.start(); impl.addAppender(appender); impl.setLevel(_level); impl.setAdditive(false); return true; } Thanks, Christopher