Balloons.io: an awesome looking realtime chat on node.js | Hacker News Reader

Balloons.io: an awesome looking realtime chat on node.js

gravityonmars.github.com

47 pointsjondot38 comments

Live demo up here if anyone else was curious: http://www.pssdbt.com:3000

If you want to run it yourself on a public-facing server, you'll need to change the connection to Socket.IO on line 2 of /public/js/script.js to point to your server instead of localhost. I also had to edit /views/themes/default/room_list.jade and put the 'each room,key in rooms' bit inside of an 'if rooms' statement because that was throwing an error.

Also worth noting, nothing is filtered (you can send <script> tags for example and they'll run for everyone).

It's also throwing a 404 error for modernizr. It's looking for it in /rooms/js/libs/modernizr..., but it's actually in /js/libs/modernizr....

This'd all be easier to confirm, obviously, if they'd have set up a demo site. Anyone else care to take a gander?

That's because they were using a relative reference, fixed it.

This could totally use a live demo.

Yes. But every chat application in node.js that has ever been presented in HN faced the same fate of being brought down to a crawling pulp whenever it had more than 100 or so concurrent users.

Which is a bit amusing, as I remember standalone IRC servers handling 40,000+ peak users with relative ease -- and that was back in the late 90s on commodity server hardware.

This makes me wonder, what is the difference in technologies? I never used IRC to be honest, was it downloadable software or was it web based? (I'm not that young I swear, I'll be 35 next week - I just didn't do chat)

No need for the past tense, IRC is very alive!

Popular GUI-clients would be Colloquy on Mac, mIRC on windows and XChat on linux. Just download one and see for yourself; Freenode is a popular network for hackers of all kinds, QuakeNet is the network for gamers (and also happens to be the biggest with ~60k users online at any given time).

you can also get support for many open source projects on their respective irc channels, most of them are on irc.freenode.net

It's just done well. It has stood the test of time, and seen nearly 30 years of development in multiple, competing irc server products. A lot of rivalry and different views and attitudes to certain strategies.

IRC is amazing. Servers are linked as leaves to hubs, or as hubs, linking to other hubs or leaves. If the network splits (one server goes down, breaking the tree) it can be quickly relinked to secondary or tertiary servers, restoring connectivity. For its time, and even to this day, it is an impressive protocol that is not only fairly easy to implement from a client perspective, but a very scalable chat server architecture.

40k might be pushing it, but 10-15k should be no problem on current hardware.

More importantly IRC servers have a battle hardened scaling solution baked right in, based on the spanning tree protocol.

Anyone looking to write a scalable chat software would be well advised to study the evolution of IRC. Anyone looking to hack a scalable chat solution would be well advised to use a mature IRCd for the backend.

No, they did handle 40k -- more, in checking my sources: peak was 58k on one server.

Citation: http://www.shortnews.com/start.cfm?id=27080

Edit: I hung out on DALnet back when twisted was still linked and when it got taken down the crush of the users, as the article mentions, rendered the network virtuall inaccessible. Goes to show what happens when you rely too much on one link.

Except wompt.com - we had over 150 in one room at one point last year.

http://balloons.io

I've yet to use Node.JS for anything yet even though I want too, it looks like Node.JS is only being used for analytics and chat applications is that all it is capable of or are people not fully using the power of Node? Balloons.io is a beautifully designed chat app, better than that of any other Node chat demo I've seen, nice one.

>it looks like Node.JS is only being used for analytics and chat applications is that all it is capable of or are people not fully using the power of Node?

Node is still immature, so it makes sense to use it in spite of the relative roughness only when it has a distinct advantage over other available technologies. Its ecosystem has also streamlined the building of server-push apps.

You can use node/express in lieu of rails or django, but it doesn't offer anything particularly interesting here. Analytics and chat apps tend to be built on persistent servers that have long-running stateful sessions, which the node ecosystem has focused on making easy... you could use EM or Twisted or Netty, but they aren't as shiny / low barrier to entry.

So, we are seeing people take advantage of the comparable strengths of a new technology that makes certain apps easier to build.

You use the right tool for the task at hand. Node is only notably useful for a relatively narrow range of applications.

For everything else, you'd much better served by using Django/Rails/etc.

And you know... streams, which allow you to easily makes bridges between software and HTTP requests; so you can make video encoding in real time (while is being uploaded) just using node + ffmpeg; or you could process a text file content at the same time is being uploaded (perhaps a database backup?) or you could quickly set up a proxy that doesn't have to store the files.

We use node.js as an API/ajax delivery server. It fits well in this realm for us.

How scalable is this? I would think it's easy to put together something that serves, say, 100 users simultaneously. But how well does this scale to 100K users?

>But how well does this scale to 100K users?

It wouldn't. Designing a system to handle 100k simultaneous users is hard, and a problem few people suffer from.

Why would you ask this question?

Why would you ask this question?

Because maybe he is looking to develop a chat system that can scale to 100,000 users? There are many instances where someone is tasked to look at a technology and understand how it scales.

Frankly, it would be helpful for you to tell us how "It wouldn't"

Because the order of magnitude is insane.

It's a) not a common problem, and b) is obviously non trivial with current technology.

The bandwidth necessary for 100k users would saturate many a pipe, and would immediately require more than one commoditized machine.

It's like saying "That's a cute little Prius you got there. How many semi trailers can it pull?"

In my experience, a single node web socket server has trouble with 5,000 concurrent connections nonetheless 100,000 connections.

No reason why it can't scale. Spawn up more processes, load balance.

It depends on how it's implemented. I used node.js to implement the websocket-based real-time aspects of my startup, Worlize, a graphical avatar-based chat platform where everyone can create their own chat world.

I use a sharded approach where each room is assigned to a random node.js websocket server when the first person enters it, and it's unloaded when the last person leaves. Just spin up more websocket servers to scale.

We have a hybrid platform with the website running on Ruby on Rails (REE 1.8.7, Unicorn, fronted by Nginx), and the real-time interaction handled by Node.js. I can tell you that the RoR servers fall over LONG before the Node.js servers even begin to break a sweat.

edit: Link to Worlize if you're curious: https://www.worlize.com/ Our Node.JS WebSocket Library: https://github.com/Worlize/WebSocket-Node

Nice!

How does it compare with Socket.io? I use Socket.io for Review19 - http://review19.com - and am always looking to experiment with new frameworks.. :-)

The two aren't necessarily the same kind of thing. WebSocket-Node is a low-level WebSocket framework. It supports both text and raw binary WebSocket messages. Socket.IO is not a WebSocket library, but sits one level higher on the stack. It's an abstraction layer that supports many different transports and overlays its own messaging semantics. For example, WebSocket-Node could theoretically provide the WebSocket transport for Socket.IO.

If you want WebSocket specifically, and don't care about falling back to long-polling techniques, or you want something that allows you to use true binary messages, look at a WebSocket library rather than an abstracted communications library like Socket.IO.

Review19 looks pretty cool! Looking forward to trying it out!

My first thought was 'oh, another node.js chat app...', but I have to say, the design is really slick - very cool.

Found an interesting bug, you can inject JS code ... give it a try on http://www.pssdbt.com:3000 demo

Just type <script>alert('JS Injection for the win');</script> on the chat box, it will execute for all members in the chat.

We fixed it!

Awesome

What does "Twitter based" mean? It uses Twitter for authentication? Or it uses bootstrap? Or tweets?

Authentication it sounds like: "Balloons uses easy-OAuth for authentication with twitter. You can easily change this code to authenticate with Facebook, for example, lets with Facebook."

Oh - and they might want to add .DS_Store to .gitignore :)

The readme isn't very well written. Would someone with Node.js/redis experience be willing to write a more comprehensive installation guide?

The challenge in chat is really scalability. I see no mention about this.

How will it scale on 10 servers?

The UI is well executed.

Reply on news.ycombinator.com