Too many sockets of Ubuntu with 'CLOSE_WAIT'

[mike442144]

• Version:6.9.1
• Platform:Ubuntu 16.04, Ubuntu 14.04
• Subsystem:?

This is a problem found inrequest, in which I also post an issue, but after a few days tracking, we found that it is not an issue with request module itself, but _http_client.js or net.js, even tcp_wrap.cc. What is strange is the proxy server sent a FIN packet to me after a Connect response, and I cannot receive end event, but when there is an error on ClientRequest, I can receive a end event as expected.

Please see the code in _http_client.js:
in socketOnData funciton, the condition path related to Connect behavior. if there is listener of Connect or Upgrade, just emit, else destroy.

else if (parser.incoming && parser.incoming.upgrade) {
    // Upgrade or CONNECT
    var bytesParsed = ret;
    var res = parser.incoming;
    req.res = res;

    socket.removeListener('data', socketOnData);
    socket.removeListener('end', socketOnEnd);
    parser.finish();

    var bodyHead = d.slice(bytesParsed, d.length);

    var eventName = req.method === 'CONNECT' ? 'connect' : 'upgrade';
    if (req.listenerCount(eventName) > 0) {
      req.upgradeOrConnect = true;

      // detach the socket
      socket.emit('agentRemove');
      socket.removeListener('close', socketCloseListener);
      socket.removeListener('error', socketErrorListener);

      // TODO(isaacs): Need a way to reset a stream to fresh state
      // IE, not flowing, and not explicitly paused.
      socket._readableState.flowing = null;

      req.emit(eventName, res, socket, bodyHead);
      req.emit('close');
    } else {
      // Got Upgrade header or CONNECT method, but have no handler.
      socket.destroy();
    }
    freeParser(parser, req, socket);

As I said above, in my script, I got Connect event correctly, but the server sent FIN packet to me after that, and I cannot get end event, why? follow is the document of net_event_end, Anybody can help?

Thanks very much.

[mike442144]

Could anybody give me a hand?

[bnoordhuis]

Can you post steps to reproduce or do you have a standalone (preferably minimal) test case we can try? It shouldn't use anything but core modules.

Also, did you search the bug tracker for similar reports? I remember there have been one or two but they turned out to be resource leaks in the application, not bugs in node.js.

[mike442144]

@bnoordhuis Actually, it is not a http issue, I have found the problem in tunnel-agent module, I'll close the issue first. thanks.