async.js parallel not working correctly

Question

I have the following code:

               async.parallel({
                    one: function(callback) { gps_helper.get_gps(PEMSID, conn, start, stop, function(fullResults){
                        callback(fullResults);
                    }) },     //query for new dataSet
                    two: function(callback) { admin.getTh(function(gpsThresholds){
                        callback(gpsThresholds);
                    }) }
                },                                      
                function(results){

                    console.log(results);
                    console.log('emitting GPS...');
                    socket.emit('GPS', {gpsResults: results.one, thresholds: results.two, PEMSID: PEMSID, count: count, length: PEMSToDisplay.length, checked: checked});     
                    count++;      
                });

This isn't working, my console displays the first query that finishes in the callback as results. There also is no {one: fullResults, two: gpsThresholds} formatting in the output, it's just displaying the callback value form the respective functions.

Answer 1

The first argument of the async callback should be the error object, so it should really be returning null if everything was ok

function(err, results){
     console.log(results);
     console.log('emitting GPS...');
     socket.emit('GPS', {gpsResults: results.one, thresholds: results.two, PEMSID: PEMSID, count: count, length: PEMSToDisplay.length, checked: checked});     
     count++;      
 });

same goes for the callbacks

callback(null, fullResults);

etc, to pass null to the error handler the async callback.
There's an example in the documentation showing exactly how it's done.