Socket.IO + Vanilla JS

vanilla.js

var request = require('request-json'),
    express = require('express'),
    app     = express(),
    http    = require('http').Server(app),
    io      = require('socket.io'),
    db      = require('mongodb').MongoClient;

///////////////////////////////////////////////////////////
// boilerplate code: ignore
//

app.get('/', function(req, res) {
  res.sendFile('./static/index.html');
});

app.post('/api/log', function(req, res) {
  var x = ((Math.random() * 10) > 5) ? "NOT\nJSON" : true;
  res.send(x);
});

app.get('/api/weather', function(req, res) {
  res.send({
    "main": {
      "temp": (Math.round(Math.random() * 1000) / 10)
    },
    "weather": [{
      "main": "Cloudy"
    }]
  });
});

app.use(express.static('./static'));

http.listen(3000, function() {
  console.log(new Date(), 'started server');
});

io = io(http);

function getFunFact(callback) {
  db.connect('mongodb://127.0.0.1:27017/library', function(err, _db) {
    _db.collection('facts').findOne(callback);
  });
}

///////////////////////////////////////////////////////////
// demo impl below
//

function log(id, messages, callback) {

  function attempt(retries) {
    request
      .newClient('http://localhost:3000/api/')
      .post('log', { messages: messages }, function(err, response) {
        if (!err) callback(err, response);
        else {
          if (retries < 0) callback(err, response);
          else {
            setTimeout(function() {
              attempt(retries-1);
            }, 100);
          }
        }
      });
  }

  attempt(10);
}

var messages = [];

io.on('connection', function(socket) {
  socket.broadcast.emit('message', 'CONN: ' + socket.id);

  socket.on('message', function(msg) {
    io.emit('message', socket.id + ': ' + msg);

    if (messages.push(msg) === 20) {
      getFunFact(function(err, fact) {
        if (err) throw err;

        io.emit('message', 'Did you know that: ' + fact.text);
      });

      log(socket.id, messages, function(err) {
        if (err) throw err;
        // otherwise OK
      });

      messages = [];
    }
  });
});