Memory leak problems Nodejs ( can't debug it with v8profiler )

Question

I'm having some memory issues in a nodeJS application that is currently on production ( a proxy to S3 multipart upload server ) so I'm trying to search for a way to detect and prevent it.. I came across this tutorial but when I open the debug page the profile tab is not showing ( after I've followed the steps from the tutorial ). Am I doing something wrong? ( I'm following this tutorial https://github.com/felixge/node-memory-leak-tutorial )

If it helps, this is a part of my code that MIGHT be causing the leak:

IngestionClient.prototype.multipartUpload = function(params, req, res, aReqLength) {
var self = this;
var client = this.client[params.profile];
var dest = params.file;

logger.debug('PART ' + params.query.partNumber + '/' + params.query.totalSize +': BEGIN : '+req.headers['content-length']+' bytes : ['
        + params.file_id + ']');

var amazonRequest = client.request('PUT', '/' + dest
        + '?partNumber=' + params.query.partNumber + '&uploadId='
        + params.query.uploadId, {
    'Content-Length' : req.headers['content-length']
});

var partLength = 0;

req.on('data', function(data) {
    partLength += data.length;
    amazonRequest.write(data, 'binary');
});

req.on('end', function() {
    if(partLength == req.headers['content-length']) {
        logger.debug('PART ' + params.query.partNumber + '/' + params.query.totalSize +': CLIENT_RECEIVED_COMPLETE : ['
                + params.file_id + ']');
    }else {
        logger.error('PART ' + params.query.partNumber + '/' + params.query.totalSize +': CLIENT_RECEIVED_INCOMPLETE : Esperado '+req.headers['content-length']
        +' bytes / Recebido ' + partLength + ' : [' + params.file_id + ']');
        amazonRequest.abort();
        self.sendError(params, res);
    }

});

amazonRequest.on('response', function(amazonResponse) {
    var responseText;

        if (amazonResponse.statusCode == 200 && amazonResponse.headers.etag.length > 0) {
            self.queryDB(
                    'INSERT INTO SAMBAFILES_UPLOAD_CONTROL_PARTS SET FILE_ID="'
                            + params.file_id + '", ETAG=' + amazonResponse.headers.etag
                            + ', PART_NUMBER="' + params.query.partNumber + '"',
                    function(err, results) {
                        logger.debug('PART ' + params.query.partNumber + '/' + params.query.totalSize +': S3_PUT_COMPLETE : ['
                                + params.file_id + ']');            
                        responseText = '{"success": true}';
                        res.end(responseText);
                        self.checkComplete(params, dest);
                    });
        } else {
            var responseBody = "";
            amazonResponse.on('data', function(dataRes) {
                responseBody += dataRes;
            });

            amazonResponse.on("end", function(){
                if(responseBody.indexOf("<Code>RequestTimeout</Code>") > 0) {
                    //Erro de lentidao do envio ( + de 20 segundos ). Browser fará um retry
                    logger.error('PART ' + params.query.partNumber + '/' + params.query.totalSize +': S3_PUT_ERROR_TIMEOUT : Response Code ' 
                            + amazonResponse.statusCode + ' : [' + params.file_id + ']');
                }else {
                    logger.error('PART ' + params.query.partNumber + '/' + params.query.totalSize +': S3_PUT_ERROR : Response Code ' 
                            + amazonResponse.statusCode + ': ' + responseBody + ' : [' + params.file_id + ']');
                }
                amazonRequest.abort();
                self.sendError(params, res);

            });

        }

        console.log(util.inspect(process.memoryUsage()));

}).end();

};

Basically in each part that I receive from the browser I make a request to Amazon using the params and request received. Node version is 0.6.7

Thanks!

Answer 1

Mozilla team released node-memwatch, a nodejs module for tracking memory leak.

Official mozilla post : https://hacks.mozilla.org/2012/11/tracking-down-memory-leaks-in-node-js-a-node-js-holiday-season/

Github of the project : https://github.com/lloyd/node-memwatch

It looks very interesting and very promising.

Answer 2

The following plugin has been updated to work with new version of v8. It's the only one besides nodetime.com that is still working. It uses the actual webkit debugger:

https://github.com/c4milo/node-webkit-agent

It has very clear instructions as well.

Answer 3

I suggest the tool http://search.npmjs.org/#/nodeheap. You can take a snapshot at anytime and compare what is still on the heap and use the tool to trace who the owners are.