René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Redirecting from socket hangs with large data","articleBody":"_I also posted this to nodejs bug tracker (joyent/node#25823), but the issue is also present in iojs 3.0.0 so it felt appropriate to report it here as well_\n\nI've been spending lots of time tracking this down for [multer](https://github.com/expressjs/multer), and form-data/multipart file uploader for express. Basically what we want to do is; whenever there is an error 1) `unpipe` the request 2) `.resume()` the request so that the browser will consider the request done.\n\nThis is implemented something like the code below. `req` is an http request from a browser.\n\n``` javascript\nfunction abort (err) {\n  req.unpipe(parser)\n  req.resume()\n  next(err)\n}\n```\n\nIt has been working great, most of the times. It seems like there is a problem when the stream contains too much data. For some reason it just doesn't emit any more `data` events, and the browser is stuck on `uploading (xx%)`.\n\nI've managed to track this down and have a small test-case that is easily replicated. The problem goes all the way down to `net.Socket`.\n\nCalling `req.resume` after `socket.pipe(out2)` doesn't help.\n\nIf the size of each buffer (`560000`) is lowered it starts working. The break point on my machine is at 16 KiB, a.k.a `1024 * 16` doesn't work, but `1024 * 16 - 1` works.\n### The test case\n\n``` javascript\nvar net = require('net')\nvar stream = require('stream')\n\nvar port = 5433\nvar app = net.createServer()\n\nfunction logStream (name) {\n  var out = new stream.Writable()\n\n  out._write = function (chunk, encoding, cb) {\n    console.log('[server][' + name + '] received chunk of data')\n    this.emit('chunk-received')\n    cb(null)\n  }\n\n  return out\n}\n\napp.on('connection', function (socket) {\n  var out1 = logStream('out 1')\n  var out2 = logStream('out 2')\n\n  out1.once('chunk-received', function redirect () {\n    console.log('[server] redirecting to `out 2`')\n    socket.unpipe(out1)\n    socket.pipe(out2)\n  })\n\n  socket.pipe(out1)\n})\n\napp.listen(port, function () {\n  var socket = new net.Socket({ allowHalfOpen: true })\n\n  socket.connect(port, function () {\n    setInterval(function () {\n      socket.write(new Buffer(560000))\n    }, 100)\n  })\n})\n```\n### Actual output\n\n``` text\n[server][out 1] received chunk of data\n[server] redirecting to `out 2`\n```\n### Expected output\n\n``` text\n[server][out 1] received chunk of data\n[server] redirecting to `out 2`\n[server][out 2] received chunk of data\n[server][out 2] received chunk of data\n[server][out 2] received chunk of data\n[server][out 2] received chunk of data\n[server][out 2] received chunk of data\n[server][out 2] received chunk of data\n...\n```\n","author":{"url":"https://github.com/LinusU","@type":"Person","name":"LinusU"},"datePublished":"2015-08-07T12:01:22.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":8},"url":"https://github.com/2323/node/issues/2323"}