server-sent-events

I have a Node.js application on Heroku. I've recently switched a long query to use SSE (EventSource). While it works great and fast on my machine, I keep getting an Error H15 (Idle connection) on my GET request. The H15 description says I went over 55 seconds allowed per transaction. But my entire query doesn't take more than 4-5 seconds. Furthermore, after reading the description, I'm returning my first byte (just a number) immediately upon hitting the query, before it starts any heavy work - and it still doesn't work. My question/s are: What do I need to do in order to keep this thing going?

I'm trying to send JSON data to the browser with SSE but I can't seem to get it right and I don't know why. Server side looks like this: var express = require("express"), app = express(), bodyParser = require('body-parser'); app.use(express.static(__dirname + '/')); app.use(bodyParser.urlencoded({ extended: true })); app.use(bodyParser.json()); var testdata = "This is my message"; app.get('/connect', function(req, res){ res.writeHead(200, { 'Connection': 'keep-alive', 'Content-Type': 'text/event-stream', 'Cache-Control': 'no-cache' }); setInterval(function(){ console.log('writing ' + testdata)

So I understand the concept of server-sent events ( EventSource ): A client connects to an endpoint via EventSource Client just listens to messages sent from the endpoint The thing I'm confused about is how it works on the server. I've had a look at different examples, but the one that comes to mind is Mozilla's: http://hacks.mozilla.org/2011/06/a-wall-powered-by-eventsource-and-server-sent-events/ Now this may be just a bad example, but it kinda makes sense how the server side would work, as I understand it: Something changes in a datastore, such as a database A server-side script polls the

All, HTML5 Rocks has a nice beginner tutorial on Server-sent Events (SSE): http://www.html5rocks.com/en/tutorials/eventsource/basics/ But, I don't understand an important concept - what triggers the event on the server that causes a message to be sent? In other words - in the HTML5 example - the server simply sends a timestamp once : <?php header('Content-Type: text/event-stream'); header('Cache-Control: no-cache'); // recommended to prevent caching of event data. function sendMsg($id, $msg) { echo "id: $id" . PHP_EOL; echo "data: $msg" . PHP_EOL; echo PHP_EOL; ob_flush(); flush(); }

I have been developing a nodejs server to provide server-side-events for a new website I am developing in HTML5. When I telnet to the server it works correctly, sending me the required HTTP response headers followed by a stream of events that i am presently generating every 2 or 3 seconds just to prove it works. I have tried the latest version of FireFox, Chrome and Opera and they create the EventSource object and connect to the nodejs server OK but none of the browsers generate any of the events, including the onopen, onmessage and onerror. However, if I stop my nodejs server, terminating the

Is there a big difference (in terms of performance, browser implementation availability, server load etc) between HTML5 SSEs and straight up Ajax polling? From the server side, it seems like an EventSource is just hitting the specified page every ~3 seconds or so (though I understand the timing is flexible). Granted, it's simpler to set up on the client side than setting up a timer and having it $.get every so often, but is there anything else? Does it send fewer headers, or do some other magic I'm missing? Ajax polling adds a lot of HTTP overhead since it is constantly establishing and