I have been tasked to develop a mobile chat app that will run both on Android and iPhone devices. I will be developing the respective clients in their native languages. Where I am a bit confused is in the development of the server.
My intended approach is to use 'long polling' to retrieve messages from the server and a separate connection to send messages to the server using GET/POST (obviously, there is no need for this to be long polled). My initial intention was to use Apache & PHP?MySQL for the server, but after a bit of reading, I learnt Apache won't be able to survive when there are lots of concurrent connections. I also learnt Node.js can survive where Apache failed by its capabilities to handle a lot of concurrent connections. Though, I don't have any knowledge about Node.js but if it will work, I am willing to do a crash course on it.
I know 'long polling' isn't the best method, but I can't seem to understand how XMPP can work for me on this project.
Thanks a lot in advance.
XMPP is the best way. You can install openfire on server side and for android you can use asmack. For Ios you can use xmpp lib.These are best combination. Communication with server is done through ssl connection.
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I am trying to build video conferencing web application where multiple people can join the call and there will be video/audio/data transmission. I researched a lot for this. What i understand is we can achieve this using webRTC protocol. I started doing research for js libraries and i came to know for simpleWebRTC. I want to develop with backend as a django. I tried to run sample demo code from https://www.sitepoint.com/webrtc-video-chat-application-simplewebrtc/. but i am not able to establish connection with socket.io which is simplewebRTC signaling sandbox server.
I tried with node express server as well, but still i got the same error:- net::ERR_FAILED. This error occured in simplewebrtc-with-adapter-js while making connection.
What would be the correct technologies to achieve this type of functionality?
Front-end webRTC libraries:- simplewebRTC/ EasyRTC/ Any else apis?
Signaling mechanism:- What and how can we use to connect with webRTC?
Backend:- Node js/Django?
I still confused with the signaling protocols/STUN/TURN servers as we have to define the servers by our self. simpleWebRTC is not providing that which we can use in production.
Any help would be much appreciated!
I just started a video calling and chat application as well. open-easyrtc, no problems so far, their demo just works after npm install.
As for signaling servers, since I just started I haven't concerned myself much about them but the most I can make out of it is it's used for exchanging information like video metadata, network information, etc. open-easyrtc comes with public STUN and TURN servers, not sure about the limitation especially if you're going to have a lot of users.
It's also possible to deploy your own, I'm looking at learning more about coturn
once I finished developing my application.
You can use simple-peer, a simple library for webrtc. Here is an example project with multiple users project, DEMO.
I have VPS hosting for a business application. It has XMPP based chat with Openfire which is working fine.
I want a real time notification system as well in our system.
I have these options
Ajax Long Poll
PHP websockets
Node.js
Using XMPP(Not sure if applicable)
Among all the above. Which one would be the quickest one?
XMPP over websocket would be a good fit as it simply builds on your existing infrastructure.
I want to make a desktop application (since its supposed to be cross-platform, I've decided to stick with Qt, and I am already familiar with it) which connects to a server. The app is similar in concept to a chat application. I know that there are application servers, however as of now, I'm familiar with web server frameworks such as rails, and am trying out node.js currently.
I wanted to know how should I ask my application(Qt-based) to connect to the server, and the main question is, how should I implement the server? After thinking up of various options, including porting the whole project over to as a web-app, I've decided that the best bet would be to use the app to somehow connect to the node.js server and it will serve the html files which will contain the command for the app. Am I on the right path?
Can this (Qt-app & node.js server communication) be achieved in the way I am thinking? Is it the correct method?
It is easy to communicate with node.js app by socket. Using node.js to create a Net server (http://nodejs.org/api/net.html), and client use socket to connect to it. In my opinion it is easier to build a server with Node.js than C/C++ and has nice performance.
BTW, I think using node.js as server has gradually become a common solution. And My company have developed a mobile game with pomelo which is a node.js game framework.
For more infomation you can see this article http://www.toptal.com/nodejs/why-the-hell-would-i-use-node-js
I have built a multiplayer game with real time leader board. The game is in PHP(Backend) + Flex(Front end).
I have used socket.io for real time communication with a node.js server. But I am facing a lot of problem with respect to proxy settings on my client network configuration. Most of the time my application doesn't communicate with my node(socket) server. It is not able to establish a connection because of proxy configurations.
What alternatives can I go with? I tried to search a lot for alternatives. I came across services like pusher and pubnub, but those are little expensive. Have anyone tried Amazon SNS, is it suitable for this?
Thanks!
The reason that you cannot connect through proxies, is because socket.io is using web sockets. See Socket.io and firewall Software (that page also includes a link to test websocket connectivity). There are a number of ways you can mitigate this problem:
Use secure websockets (wss://)
But this does also not guarantee for 100% that it will work.
Use one of the fallback mechanisms of socket.io: Flash, Ajax, iFrame, JSONP, ...
For more information, see Configuring Socket.io.
There is SocketCluster: https://github.com/topcloud/socketcluster
It runs on multiple CPU cores and it's good with error-handling (workers auto-respawn). It has no identified memory leaks (just make sure you use latest version of Node.js).
How can I send low latency data to a server and back with phonegap?
Considering I don't have access to php files locally, and don't have experience with node.js or WebSockets I don't know which ones I should use.
WebSockets aren't natively supported by the browsers in Android or older versions of Cordova under iOS, which means you'll need to use a PhoneGap plugin if you want to use them on the client.
There's more information at: http://remysharp.com/2010/10/04/websockets-in-phonegap-projects/
However, I'm not sure (even with the plugin) how resilient WebSockets are likely to be when the device moves between network connections (WiFi -> 3G -> WiFi), so using a simple polling web service may be a more reliable option if your app needs to continue receiving data as your users move around.
If you need to receive data initiated by the server, consider using push notifications instead: both iOS (APN) and Android (C2DM) provide APIs to do this which make more efficient use of the battery than having your app poll your server constantly.
You can use WebSockets in PhoneGap with iOS and Android. WebSockets are natively supported on iOS within Safari. For Android you will need to use a polyfill.
See: https://stackoverflow.com/a/13527585/39904
The answer above provides information about how to make a WebSocket object available within the Android WebView used by PhoneGap and also provides a link to a sample project which you can use to get started.
WebSockets were developed as a solution to 'Comet' hacks. As such they provide a very low latency solution for realtime bi-directional communication between a client and server. This means low bandwidth and low resource usage - battery on mobile - since you are holding a single connection open rather then opening and closing multiple HTTP connections. A polling solution which makes requests at regular intervals is likely to drain the battery much faster than a WebSocket solution. If you are polling at lower intervals then it may be fine - it depends on your use case.
In terms of WebSockets working as you change between network and network type (WiFi -> 3G -> WiFi) then if you are using WebSockets natively you need to detect the onclose and reconnect. You will also need to determine the best type of connection; unsecure (WS) or secure (WSS). I would highly recommend you use WSS for mobile since some mobile network providers use transparent proxies which interfere with WS connections. This might sound complicated but there are a number of libraries that handle this for you. Such as the Pusher JavaScript library (note: I work for Pusher). Libraries such as these also provide fallback to a less efficient HTTP-based solution when the environment will not let any WebSocket connection occur.
Also see: realtime web technology guide.
I'd agree with #rmc47 that you should consider native push notifications if it's for infrequent single notifications
Refer to this link to see WebSocket Support by Browsers and devices : html5test.com site - iOS 4.2+ already supports WebSocket
See this doc that explains how to develop a simple application with WebSocket.
Unfortunately the content is in the Portuguese (Brazilian) language but you can leave comments which I will answer.
I'm not sure what you mean by "access to PHP files locally". The use of node.js and web sockets is also not mutually exclusive.
If you have not made a decision on the server implementation you could go for either node.js or ASP.NET.
node.js has good support for sockets with Socket.io, which abstracts the client implementation for you. So it will use WebSockets if there is support, else it will fall back to long polling.
ASP.NET has a library called SignalR which does something similar for the .NET platform.