I'm going to build an webbased application which is controlling and monitoring tons of realtime data. think about few thousand valves pipes pumps and sensors.
Please list a technology stack you would use to build a realtime website with an educated guess about performance. The environment is 'ideal' all openstandards are available. so no IE6 etc backward compatibility is needed. Current and future proof technologies please.
server side:
database web-server - which one / combination makes it easy to support real-time pushing of data?
client side:
what kind of client environment (javascript Libraries) support showing and updating tons of realtime data?
You can have a look at Goliath
I recommend you have a look into Socket.IO which works best with Node.JS and might be the best fit for handling many long lasting concurrent real time connections. I would say that the choice of the database depends more on where your real time data is coming from and how it is supposed to get in the database.
Me too. So I'm writing a frame work that can do that. It's based on lighttpd front end, and multiple fcgi backend servers. The original Android was also tested with another framework that is based on it. It's open source so you might want to use it as a starting point.
I haven't been able to write a realtime app, but I've dabbled a bit with http://socket.io/ and node.js, and it's a joy to get started with.
App engine has a js channel api which seems nice. You should take a look to see if hosting on app engine is a option.
If you're dealing with "real time" stuff server-side, I recommend clojure for managing concurrent state.
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First off, I am not asking for any code or anything like that.
all I need is some advise.
I'm creating a roulette game and everything in my roulette game is based on jQuery.
however, as we all know, jQuery is client side so I was thinking about using AJAX to send some details back to server and from the server to the users browser so I can make this roulette game work in "multiplayer" fashion... But the issue is that I don't think its possible to send the roulette's wheel animation to the server and back to users browser so I am a bit confused about this!
In my research I came across some information (old ones) about using node.js and jquery together! I don't know if this is possible or how easy it would be to use my jquery code in node.js as I have never used node.js before..
so the question that i have is:
based on the information i provided above and my requirements, what are my options?
can I use AJAX to achieve what i am trying to do and if so, a bit
information would be great.
if AJAX is out of question, is it possible to use my jquery code in
node.js to achieve what I am trying to do?
ANY ADVISE WOULD BE APPRECIATED.
P.S. I don't want to use HTML5 as 1st I don't know much about HTML5 and also, some devices, browsers do not support it.
Thanks
The best way is to use websockets to ensure real time communication. One of the best alternatives for implementing that could be using a server under node.js. Have a look to this video from Code School node.js tutorials: https://www.youtube.com/watch?v=mtDK4jf4RS0 where is ilustrated how to implement a real time chat. Your problem is based on the same.
There are three parts to a multiplayer game displayed in a browser:
client-side display,
server-side data management,
client-server communication.
If you're already set on your display technology (jQuery), then you're probably going to use $.ajax() for client-server communication. However, technologies used for server-side data management are completely up to you and they don't necessarily have any connection to the technologies used for display and communication (meaning the traditional communication initiated by client).
Basically, use any kind of server technology stack you like. Node.js might do just fine but there are many other viable alternatives. They just need to support communication with the client.
So, to be absolutely clear, your question doesn't really make sense. You might use jQuery in the client and Node.js on the server, but they will never really "work together". They will manage completely separate parts of your application and connect through protocols not specific to either of them.
As for the animation, the animation itself is solely a client-side problem. If you want to "synchronize the animation" across multiple clients, you can let the clients communicate with the server, but they only ever need to send/receive plain data. Then you adjust the client-side animation based on the received data.
As another poster points out, websockets are a better fit for this than regular client-initiated HTTP requests. Not because of "the animation", but because you want all the clients to receive the information about the start of betting at the same time.
I am also developing a MMO game using javascript only. Firstly, there are two different types of javascript here. Usual client side javascript (the one you already know) and the server side javascript (i.e. Node.js).
You will need to develop both client and server before connecting them with jQuery's Ajax. So you need to study Node.js before designing overall architecture of your game.
I read many Node.js tutorials and watched many youtube tutorial videos but I was still confused, before I really sat down and read a good textbook that explained from basics, one like below. Try to get hold of it from your local library.
Express web application development learn how to develop web applications with the Express framework from scratch by Hage Yaapa
Express is the popular framework that runs on Node.js now. So it's worth getting familiar with Express Framework. Once you understand how express app works (not so difficult), you will see how you can frame your game structure like I did :)
In order for many clients to share same animation, there must a server that synchronizes the game state. Ajax can only link between server-client communication in my understanding. There is no mechanism that connects between clients. The clients ask server what number was the result of roulette roll and show the corresponding animations.
Yes, you can use NodeJS and jQuery together.
NodeJS is server-side, meaning that you set up a server (a lot of people use the Express module, which is easy to use), which serves content to clients asking for it. Your server-side code can be in any language supporting sockets, not just NodeJS. But NodeJS is easy to use if you know JS already.
jQuery is client-side, meaning that it's executed by the user's browser, and may or may not have a server-side component (if it doesn't need it), or it might have one where it sends requests to the server-side code. When it requests a page from the server, it can be static content (like when you request index.html) or dynamic via an AJAX request. Client-side browser code must be HTML/CSS/JS (you can't make Firefox or Chrome interpret C, for example).
I am required to implement a live chat system, somewhat similar to Facebook's in that it must:
Allow communication between 2 users
Store messages in an inbox/sent box
Store messages in inbox, marked unread if the user is offline when a message is sent
A language/spam filter must also be active, as needs to monitor communication involving minors.
Ideally, this will work on most devices/browsers including mobile access.
I pretty much have a blank canvas for this project in terms of what OS/software to use.
Having done a bit of research it seems like there's a few options / things to think about?
PHP/AJAX long polling (Comet-style) with a standard LAMP stack storing messages in a mysql DB
LEMP stack (nginx)using the HTTP Push Module, again Comet-style server with a php backend storing messages in a mysql DB
Node.js?
HTML5 interface to maintain browser/device support?
Best DB system for this? Some people suggested mongoDB?
Some people also suggested utilising MemCacheQ to boost performance.
What are your thoughts this? Any suggestions?
Check out SignalR as the way of passing the messages between clients, it's the easiest way to create a chat application.
This sounds like the sort of thing that the MEAN stack (MongoDB, Express.js, Angular.js, Node.js) combined with either socket.io, or lightstreamer would be good at. Lightstreamer is supposedly faster and more scalable than socket.io (and their live demo's don't make me doubt that), it also has a page in their documentation discussing PhoneGap (they handle phones that don't support WebSockets...which is useful, because, as I understand it, WebSockets aren't supported by most phones)
This isn't my area of expertise though, but it may be worth researching.
Has anyone an idea for the following scenario?
I have a RIA-Webapplication (realized in ExtJs). What I want to implement is the possibility to use local ressources like card readers or fingerprint readers or other serial devices and filesystem access.
I thought about implementing this with a local websocket service which has to be installed by our customer before using our RIA the first time. When the webapp is loading it should scan the local machine if a websocket service is available and connect to it.
After that, local events (like new card is beeing read or recognized new finger) should be passed to the browser via websocket connection.
Any ideas how to get started with such a solution?
I have made something like that. Besides the obvious things such as read/write/poll data from the card-readers and so on, you would have to either implement everything yourself or, use a library for technology you are going to employ for your web-server. So, if you use a LAMP solution, i think there are some web-socket libraries for PHP that you can use. However, if you do everything by yourself then you have to implement everything from hand-shaking, to creating data packets. I have done everything from scratch by using .NET and it provides a number of useful libraries such as hashing. Java also would be a good option and have those kind of libraries as well. In general if you doing everything by yourself i would say the trickiest thing would be to split the data you want to transmit among various data packet. It is not that hard to do things from scratch. The RFC (https://www.rfc-editor.org/rfc/rfc6455) helped me a lot. Hopefully, this helps.
Anyone knows a good tutorial/js plugin to create a multi user html5 sketch web application?
Would be nice to have cross browser compatibility, preferably without any tools that need to be installed server side.
If the latter is not possible, I would also be happy if the application just saves the user x's sketch so that next time someone loads the app, it would show user x's sketch on startup.
Thanks for your advise.
PS. I have looked at Mr. Doob's, he uses node.js, unfortunately my hosting does not support this just yet. Hence I am asking for a solution that need no server side installation. Also the multi user drawing pad by Union Platform seems to fit the bill, but unfortunately it also requires something to be installed.
If you're willing to shift to a new web host for this application you can use Heroku. Heroku is free and supports Node.js.
I created a multi-user Agile project management whiteboard using WebSockets and Node.js and found a 624% increase in requests per second vs using HTTP. I use MongoDB on the back end which allows you to store data as serialized JSON... this means you can send JSON between client <-> Server <-> Database with no parsing (very fast).
Hope this helps!
The reason Mr. Doob's implementation uses Node.js is because node is great at this kind of things. Since this is going to involve delivering realtime changes to different users, your best bet is to use Comet/Ajax-Push/Longpolling. And if you want to support multi-window usage(multiple browser tabs having your sketchpad), you would need to implement http connection pooling to get around the connection limits set by browsers as per http standard.
If you can't use websockets which are fairly new anyways, Then I would suggest using ajax polling of some sort. Basically use ajax calls based on a delay.
This wikipedia article shows some of the various options you should do further reading into.
http://en.wikipedia.org/wiki/Comet_%28programming%29
I'm trying to put together a small(ish) summer school project for some of my advanced students and am researching how to do it best and what to use - hopefully somebody here could point me in the right direction.
What we are interested in is researching if HTML5 came far enough to create a real-time collaborative drawing whiteboard in it - purely by using web technologies without plugins (so CSS, HTML5/DOM and Javascript). What we'd ultimatelly strive for is this - for example have an online canvas/page on a central server displayed on a big screen in the classroom. Then our students/users would take out their smartphones, load the page in their mobile browsers (I'm perfectly ok with limiting this to webkit mobile browsers for now) and draw on their screens with touch/fingers (or on PCs with the mouse - guessing this doesn't make a lot of difference) and it would get updated in real time for everybody - both on their screens and on the central big screen in the classroom.
I'm guessing push/get requests would be too slow for this - could it be solved by websockets? Does anybody have any good JS libraries to recommend for this?
Also what would the ideal (but easier for students to understand) architecture look like. Lets say you have 30 simultaneous users in a clasroom - each of them would connect with websockets to the server and the server would pool/combine all of their requests into one and then return the combined file (some sort of minimal JSON or even just coordinates) for every connected user?
Would websockets and (I'm guessing) canvas be able to take this? So that everything still looks snappy? Are there (jQuery-like) JS libraries available to make our lives easier - or do you think its something thats too complex for a 2-week summer school project?
here's a tutorial describing how to create a multiuser whiteboard with javascript/html5/canvas:
http://www.unionplatform.com/?page_id=2762
the example uses a collaboration framework and server named "union platform". even if you decide to roll your own server and client framework, the messaging in the example should give you an idea of how to structure the code.
for an apples-to-apples speed comparison of websocket vs comet, see:
http://www.unionplatform.com/?page_id=2954
in my tests, a basic ping over WebSocket is normally about twice as fast as the ping over http. both websocket and coment are more than fast enough to create a collaborative whiteboard.
Definitely check this out:
http://wesbos.com/html5-canvas-websockets-nodejs/
For the networking side of things, try looking at node.js for the server, along with socket.io for the client.
As for the drawing itself, a few popular choices are processing, raphael and cakejs.
When it comes to the implementation, you may want to look at how networked games deal with similar issues (gamedev.stackexchange.com could be useful).
What you are going to be doing is essentialy the same as a simple top down multiplayer game, with each 'player' in this case being a students fingertip, and the 'level' being the canvas. You need to update the server as to their position and whether or not they are 'shooting' (drawing).
I'm guessing push/get requests would be too slow for this - could it be solved by websockets? Does anybody have any good JS libraries to recommend for this?
If you need real-time infrastructure I've created a list of real-time technologies which might be of use to you. These include hosted service, such as Pusher who I work for, and self-install technologies such as WebSocket and Comet solutions.
WebSocket sounds like the idea choice of technology for you since they have become part of HTML5 and offer the most efficient for of realtime bi-directional communication between a web server and a browser (or other clients).
Also what would the ideal (but easier for students to understand) architecture look like. Lets say you have 30 simultaneous users in a clasroom - each of them would connect with websockets to the server and the server would pool/combine all of their requests into one and then return the combined file (some sort of minimal JSON or even just coordinates) for every connected user?
It sounds like you should probably store the current state somewhere and on the initial load of the application display that state. Then use your real-time infrastructure to send deltas on that state, or if it's a drawing on canvas, just information on the line etc. that has been drawn and information about who drew it.
Would websockets and (I'm guessing) canvas be able to take this? So that everything still looks snappy? Are there (jQuery-like) JS libraries available to make our lives easier - or do you think its something thats too complex for a 2-week summer school project?
Real-time collaborative drawing is most definitely achievable and there have been a number of examples created of this. A google bring up a number of possibilities.
If this technology is completely new to you and you would prefer to concentrate on building the collaborative application then I would consider using a service for your app rather than going through the hassle of learning how to install and configure, or even code, your own infrastructure (I'm not just saying this because I work for such a service. I honestly think it makes the most sense).