code: function serverMonitoringCleanup(db, conn){
      var exclude = {
          eventDate: 0,
          pid: 0,
          version: 0,
          uptime: 0,
          network: 0,
          connectionName: 0,
          connections: 0,
          memory: 0,
          dataRetrieved: 0,
          docCounts: 0
      };
  
      var retainedRecords = (24 * 60) * 60 / 30; // 24 hours worth of 30 sec blocks (data refresh interval)
  
      db.find({connectionName: conn}).skip(retainedRecords).sort({eventDate: -1}).projection(exclude).exec(function (err, serverEvents){
          var idArray = [];
          _.each(serverEvents, function(value, key){
              idArray.push(value._id);
          });
  
          db.remove({'_id': {'$in': idArray}}, {multi: true}, function (err, newDoc){});
      });
  }
docs: Removes old monitoring data. We only want basic monitoring with the last 100 events. We keep last 80 and remove the rest to be sure.