// set up appender
final PatternLayout layout = PatternLayout.createLayout(msgPattern, ctx.getConfiguration(), null, null, null, null);
// FileOutputStream fos = new FileOutputStream(OUTPUT_FILE + "_mdc");
final FileAppender appender = FileAppender.createAppender(OUTPUT_FILE + "_mdc", "false", "false", "File",
"false", "true", "false", null, layout, null, "false", null, null);
appender.start();
// set appender on root and set level to debug
root.addAppender(appender);
root.setLevel(Level.DEBUG);