Socket.io - Wrong client socket event being called on server emit - node.js

Question

I am creating a load test application for my socket.io application. Very strange results are happening when there is an DB error on the server side. Upon DB deadlock, the server emits the correct event, but on the client side the wrong event is being called.
Server code:
(I even got rid of all DB code and just output what the DB would output so
I know it's nothing to do with the DB)
function AddUser(gObj, cb) {
if (gObj.UKEY==2)
cb({err: 901, errm: "deadlock baby"});
else if (gObj.UKEY==3)
cb(null, [3,0,0,1,0]);
else
cb(null, [1,1,0,1,0]);
}
var io=require('socket.io')(8080);
var iowm = io.of('/mpp');
iowm.on('connection', function(socket) {
console.log('in MPP connection');
socket.on('nu', function(data) {
console.log('APP: in AddUser');
AddUser(data, function(err, result) {
console.log('RC: ',data);
if (err) {
console.log(err);
iowm.emit('error', {ERRM: err.errm});
console.log('ERROR: emitted');
} else {
console.log('done: ',result);
iowm.emit('done', result);
}
});
});
});
io.httpServer.on('listening', function() {
console.log('listening on port ',io.httpServer.address().port);
});
console.log('Done...');
Client code:
(I wrap the socket events in a wrapper function (which is probably where my error is) in order to pass the right parameters to the socket events in this tight loop)
for(var i=0; i<args[4]; i++) {
age = (Math.floor(Math.random()*args[3]) + 1) * 4;
console.log('ukey: '+args[2],' age: ',age);
socket = io.connect('http://localhost:8080/mpp');
if (socket) {
var OrigSocketOn = socket.on;
socket.on = function(event, data, cb2) {
return OrigSocketOn.call(socket, event, function(res) {
console.log('ESock: ', event,' data: ',data);
switch(data.ENT) {
case 2: // connect
cb2(data);
break;
case 3: // error
cb2({data: data, result: res});
break;
default:
cb2(res);
break;
}
});
};
socket.on('connect', {ENT: 2, GKEY: args[1], UKEY: args[2], AGE: age}, function(data) {
socket.emit('nu', {GKEY: data.GKEY, UKEY: data.UKEY, AGE: data.AGE});
});
socket.on('done', {ENT: 4, UKEY: args[2], AGE: age}, function(data) {
++cnt;
console.log('SOCKET: NewUser Done cnt: ',cnt);
console.log(data);
socket.close();
if (cnt == args[4] || data[4]>0)
cb();
});
socket.on('error', {ENT: 3, GKEY: args[1], UKEY: args[2], AGE: age}, function(data) {
console.log('SOCKET: NewUser Err');
console.log(data);
if (data.result.ERRM.indexOf('deadlock') > -1) { // deadlock - try again
socket.emit('nu', {GKEY: data.GKEY, UKEY: data.UKEY, AGE: data.AGE});
} else {
socket.close();
if (++cnt == args[4])
cb();
}
});
...
Server Output:
(All looks good. UKEY 1 and 3 come back fine and it emits the 'done' event. But UKEY==2 is the deadlocked entry so it emits the 'error' event.
in MPP connection
in MPP connection
in MPP connection
APP: in AddUser
RC: { GKEY: 1, UKEY: 3, AGE: 32 }
done: [ 3, 0, 0, 1, 0 ]
APP: in AddUser
RC: { GKEY: 1, UKEY: 1, AGE: 40 }
done: [ 1, 1, 0, 1, 0 ]
APP: in AddUser
RC: { GKEY: 1, UKEY: 2, AGE: 40 }
{ err: 901, errm: 'deadlock baby' }
ERROR: emitted
Client Output: (this is the problem)
ukey: 1 age: 40
ukey: 2 age: 40
ukey: 3 age: 32
ESock: connect data: { ENT: 2, GKEY: 1, UKEY: 1, AGE: 40 }
ESock: connect data: { ENT: 2, GKEY: 1, UKEY: 2, AGE: 40 }
ESock: connect data: { ENT: 2, GKEY: 1, UKEY: 3, AGE: 32 }
ESock: done data: { ENT: 4, UKEY: 1, AGE: 40 }
SOCKET: NewUser Done cnt: 1
[ 3, 0, 0, 1, 0 ]
ESock: done data: { ENT: 4, UKEY: 2, AGE: 40 }
SOCKET: NewUser Done cnt: 2
[ 3, 0, 0, 1, 0 ]
ESock: done data: { ENT: 4, UKEY: 1, AGE: 40 }
SOCKET: NewUser Done cnt: 3
[ 1, 1, 0, 1, 0 ]
So 3 problems:
1) the client 'done' event is seemingly called 3 times, when it should only be 2 times and the 'error' event should be called once.
2) the data of the 1st and 3rd 'done' events is the same (UKEY: 1), where it should be (UKEY: 1) and (UKEY: 3)
3) (UKEY: 3) output data is not there at all.

Answer 1

It looks to me like on your server, where you to iowm.emit(...), you should be doing socket.emit(...).
Your client is apparently making multiple connections to the server as there's an io.connect() inside of a for(var i=0; i<args[4]; i++) loop. So, when you do iowm.emit(...) on the server, it sends to ALL the connections the client has, not just the one that the error occurred on.
1) the client 'done' event is seemingly called 3 times, when it should only be 2 times and the 'error' event should be called once.
Because you're broadcasting the error to all client connections, not just to the one socket that the error occured on.