code: function notify (doc) {
    // find queue, find worker...
    if (_.isArray(workers[doc.type]) && !_.isEmpty(workers[doc.type])) {
      var wkr = workers[doc.type].shift();
      // update doc as processing
      db.atomic('dequeue', 'id', doc._id, function (err, body) {
        if (err) {
          log.error(err);
          return wkr.send(ERROR, err);
        }
  
        var job = _.extend(doc.job, {
          id: doc._id,
          ok: true
        });
        wkr.send(SUCCESS, job);
      });
    }
  }
docs: if worker is listening - notify..