javascript - Very simple Node.js client throws error ENOBUFS after many http requests

Question

I have the following set up:

A node.js client makes end-to-end requests to a node.js server. After less than a minute, the client fails with error ENOBUFS.

client:

(function(){ 

        var loadUrl=function(){
            var http=require('http');   
            var querystring=require('querystring'); 
            var options = {host:"localhost",port:1337,path:'/post',method:'POST'};

            var req = http.request(options, function(res){              
                res.setEncoding('utf8');
                var body='';
                res.on('data', function (chunk) {
                    body+=chunk;
                });           
                res.on('end', function (chunk) {
                    loadUrl();   
                });   
            }); 
            req.on('error', function(e) {
              console.log('problem with request: ' + e.message);
            });
            var post_data = querystring.stringify({id:0});
            req.write(post_data);
            req.end();
        }
        setTimeout(loadUrl,1000);   
    })()

server:

var http = require('http');
http.createServer(function (req, res) {
      res.writeHead(200, {'Content-Type': 'text/plain'});
      res.end('Hello World
');
}).listen(1337, '127.0.0.1');

While this question is similar, I am posting this as a generalization of the original question (I am using post rather than get), with a test case.

Answer 1

The issue appears to be a problem with the Node.js HTTP client connection pool.

If you add the option agent:false to the options argument of the http.request() function it will disable connection pooling and have each request use the header Connection: close. This change seems to allow the client code to run indefinitely.

var options = {agent:false, host:"localhost", port:1337, /*...*/ };

Doing this will degrade the performance of the HTTP clients and you should see frequent pauses in the client process (presumably while the V8 runtime does garbage collection). But it does seem to solve your problem!

Per @joshp's comment, see if this issue has been addressed in a later version of Node.js or consider filing a bug report.