Under stress, some connections keep open

[revington]

Under stress some connections will stay on CLOSE_WAIT state.

To reproduce the issue:

$ node close-wait.js close-wait.js below
$ wrk --latency -t4 -c400 -d30s "http://localhost:8000"

$ ss -e | grep 8000 | grep CLOSE
tcp    CLOSE-WAIT 0      0            127.0.0.1:8000          127.0.0.1:40084    uid:1000 ino:2562644 sk:ffff8803a9e2db00 -->

Everytime I run the stress test a new connection (the first one) remains in CLOSE_WAIT state

close-wait.js

'use strict';
var cluster = require('cluster');
var http = require('http');
var numCPUs = require('os').cpus().length;
var proxiedHttp = require('findhit-proxywrap').proxy(http, {
    strict: false
});
var i;

if (cluster.isMaster) {
    // Fork workers.
    for (i = 0; i < numCPUs; i++) {
        cluster.fork();
    }

} else {

    // Workers can share any TCP connection
    // In this case it is an HTTP server
    proxiedHttp.createServer(function handler(req, res) {
        return res.end('ok');
    }).listen(8000);
}

[cusspvz]

Interesting... Is this test code intermittent or actually works every time?

We aren't using this at the time on production, but yet I could check it by today. ;)

[revington]

It works everytime for me

[revington]

wrk, makes a connection before performing the test (the test use another connection/s).
The behavior of node to this connection is different when http has been proxied with proxywrap.

Without proxywrap, node will (record no. 10) answer FIN ACK to wrk

With proxywrap, node will just (record no. 10) answer only ACK to wrk

[cusspvz]

I've released 0.3.11, which includes your fix! Thanks once again.

[revington]

You're welcome!

2016-01-18 15:54 GMT+01:00 José Moreira [email protected]:

I've released 0.3.11, which includes your fix! Thanks once again.

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