uncaughtException on TCP close

[boazshor]

I have a problem that accrues sporadically, I'm working on top of unstable servers (not my choice), that means that every once in a while all the connections get disconnected.
When that happens it looks like the driver doesn't reacts well:
stack:
[ 'TypeError: listener must be a function',
' at TypeError ()',
' at Connection.EventEmitter.removeListener (events.js:195:11)',
' at Query._removeAllListeners (/opt/Autonomy/shared/vertica-util/node_modules/vertica/lib/query.js:241:21)',
' at Query.onConnectionError (/opt/Autonomy/shared/vertica-util/node_modules/vertica/lib/query.js:130:10)',
' at Connection._onClose (/opt/Autonomy/shared/vertica-util/node_modules/vertica/lib/connection.js:364:23)',
' at Socket.g (events.js:180:16)',
' at Socket.EventEmitter.emit (events.js:95:17)',
' at TCP.close (net.js:465:12)' ] }

I looked at the code and it looks like a this problem:
you are trying to remove a listener:
this.connection.removeListener('EmptyQueryResponse', this.onEmptyQueryListener);

That we added in the run function:
Query.prototype.run = function() {
this.emit('start');
this.connection._writeMessage(new FrontendMessage.Query(this.sql));
this.connection.once('EmptyQueryResponse', this.onEmptyQueryListener = this.onEmptyQuery.bind(this));

which is declared on the Query:
Query.prototype.onEmptyQuery = function(msg) {
var err;
err = new errors.QueryError("The query was empty!");
if (this.callback) {
return this.error = err;
} else {
return this.emit('error', err);
}
};

Could it have something to do with the clients code?
Do you have a workaround?
Thanks.

[wvanbergen]

Yeah, this probably is an error handling problem in the client somewhere.

• My guess is that this write fails: https://github.com/wvanbergen/node-vertica/blob/master/lib/query.js#L28
• That failure will trigger this error handler: https://github.com/wvanbergen/node-vertica/blob/master/lib/query.js#L129-L140
• The error handler will try to deregister the event listeners, but they have not been set yet.

The solution would be to only unregister the listeners if they are set only. I don't have a working node.js or vertica setup available right now, so it's unlikely I will fix this myself any time soon. I will gladly accept patches for this though.