anchor.diff:        await trans.commit();
   
         // Erst nach Speichern an den Client bestätigen!
  -      await _eventQueueSink.add(e);
  +      await Future.wait([_eventFileSink.add(e), _eventFileMirrorSink.add(e)]);
   
         for (WebSocketConnection conn in connections) {
           for (Subscription sub in conn.subscriptions.values) {
  
positive.code:       this.queryHandler,
        this.eventFile,
        this.backupDirectory,
        this.authenticator,
        this.skipplayback);
  
  
negative.code: 
    /// Saves the current EventQueue in [eventFile] in a new gzipped file in [backupDirectory] ("events_milliSecondsSinceEpoch.dat")
    Future backupEvents() async {
      // First save complete chain as "backup/TIMESTAMP.dat" (gzipped)
      final File tempEventFile = new File("${backupDirectory.path}/tmp.dat");
      await tempEventFile.create(recursive: true);
      final Stream<List<int>> eventsFile = eventFile.openRead();
      final IOSink tmpSink = tempEventFile.openWrite();
  
      await eventsFile.transform(GZIP.encoder).pipe(tmpSink);
      await tempEventFile.rename(backupDirectory.path +
          "/events_${new DateTime.now().millisecondsSinceEpoch}.dat");
  
      // Now save complete chain as "backup/events.dat" which will mirror "data/events.dat"
      await eventFile.copy(eventFileMirror.path);
    }
  
    Future logAction(
  