Objective C message to all online clients - ios

I have an iOS App where people can post something to their wall. Now I would like to make a function that, when a client posts something, everyone who is online (application active state) can see a message that tells them that someone just posted something.
I have been using Sinch.com, Quickblox.com etc.
Sinch is bad, delay and slow, and it cannot send messages to over 10 clients. And it's for chatting, not for notification.
Quickblox is good, but it has a really high price and it's for chatting too.
I have tried to use PushRemoteNotification, but this depends on whether users turn on notification permission or not. Even if they enable notification, it is really slow when I send a message to over 500 clients through Push, and also I don't know which devices are online, so I believe this is not a solution.
I am planning to use PHP Ratchet WebSocket server and use one of these WebSocket libraries for my app Objective-C SocketRocket client or JetFire, but this is just my plan. So do you think it's possible for a huge amount of online clients?
If there is anyone who has any better idea please help.

I'm not entirely sure what exactly you are looking for, but I've had a lot of success using Twisted, which is built on top of Python. It has good functionality for building socket connections that allow pushing data from the server to clients. Ray Wenderlich's site has a great tutorial on Twisted (and specifically using Twisted with an iOS app) that helped me quite a lot.
Alternatively, socket.io, which is built on top of node.js would probably suit your needs quite well.

Related

Building a webRTC application with Ruby on Rails Backend

I want to implement a peer-to-peer video chat feature for a web application I am currently developing. After doing my research, I've decided that using webRTC's Javascript APIs is the way to go. The application uses AngularJS in the front end and Ruby on Rails in the back end. The main issue I'm encountering while conceptualizing this application is linking the front end with the backend, and creating and maintaining the connection between user streams.
For the signaling aspect of the network, I want to utilize ActionController::Live and the Ruby gem em-event source to push live messages from the server to users and indicate which of their connections are online. Then, when they are ready to make a connection, they will create a custom room and the URL will be sent to the user that they wish to connect with, creating their offer. Once the user clicks on the link sent to them, they send back their answer. When the user responds, the ICE candidate process will begin for each of the users. Do you think that this is a sufficient signaling channel to set up the PeerConnection? What other major players am I missing?
From the research that I have done about WebRTC's RTCPeerConnection, once the initial connection is set up, and both users have public IP addresses corresponding to their stream, the connection is sustained through RTCPeerConnection, more specifically getPeerConnection(). Am I wrong? Are there other factors that I am not considering?
WebRTC makes the process of creating MediaStreams very simple with their getUserMedia method. Once these streams are created they can be added to the RTCPeerConnection that was established. Both as local and remote streams.
If you have any other suggestions for me, please let me know. I want to create this feature using webRTC, it seems like so much fun
There are certainly many ways to handle the call signaling so I'm not going to comment specifically on your approach. I will say that if you plan on supporting ICE trickling the ICE candidates will start flowing very early in the process so you really need an open signalling channel between your peers almost immediately when trying to connect to a peer.
We developed our solution for WebSphere on top of MQTT which is an open, and very simple pub/sub protocol. You can use any open MQTT broker with the protocol and there are a number of open source components available to make WebRTC development extremely easy including an AngularJS WebRTC module (angular-rtcomm), a core pure JavaScript module and much more. We also released a simple JSON based protocol as part of this open source solution. You can take a look at the signaling protocol. You can also read more details about the overall solution here (www.wasdev.net/webrtc). Here you'll find the base JavaScript libraries as well as a number of open source sample solutions. All of these can be forked on github.
In general you want to build your signaling on a protocol that will allow you to grow over time. It should work well for the web and mobile apps. From our experience it took a lot of time to get all this to work well and our goal was to not only support peer-to-peer calls but to support using media resources like Dialogic's XMS PowerMedia server on the backend for multiway support, record/playback and more. We also needed to support federation via SIP trunking so we wanted to make sure the protocol could be easily translated to SIP signaling while also supporting transcoding between media protocols like VP8 and H.264.
Note that if you're looking to only support peer-to-peer calling between WebRTC clients you can do that with these rtcomm open source components only, including an open MQTT broker and save yourself a ton of time. You can literally get something up and running in a matter of hours. The developer version of the WebSphere Liberty beta with the new rtcomm-1.0 service enabled also includes a built in MQTT broker and supports the open WebRTC signaling protocol linked above. You can use WebSphere for development and deploy a single server of this in production for free. You can also use Ruby on Rails with Liberty as well if you'd like.
Even if you decide not to use Liberty you can use all the open source components along with something like Mosquito (which is an open source MQTT broker) to get a solution off the ground quickly. There are also a number of MQTT clients available for many different programming languages including JavaScript, Java, etc. Check out https://eclipse.org/paho/. If you decide to build you're own signaling protocol you might still find these open source components helpful to see how we approached integration with the WebRTC PeerConnection.

Using Node js in Multiplayer turn based game in ios

Hope u guys are doing great.
I want to make a realtime turn based game in iOS .
I know this can be achieved by using GAME CENTRE in iOS , but i have to play this between browser and iOS app. WEB TEAM is using node js for making this game on web browser , they also suggested me to use node js in iOS game as well.
Have anyone has idea how to use node js for this kind of purpose.
Thanking you all! :)
You can have websocket server written in node js and then just connect to it from your ios app using some websocket library (hope it exists). Then sockets connected from browser and your app can realtime exchange information.
You could use a pub/sub messaging service like Realtime (the company I work for) http://framework.realtime.co/messaging/
Both your node.js server and your ios devices could exchange data through Realtime pub/sub channels, using the node.js and ios SDKs.
The cool part is that since it's a managed service you don't need to worry about the server and networking administration, Realtime will take care of that for you.
I'd like to add some words in favor of #Edgar's answer.
For production, using only WebSocket is not reliable. In environment where WebSocket is not available due to antivirus, enterprise firewall, and so on, a kind of full duplex connection over HTTP should be available utilizing long polling or streaming in terms of reliable real-time connection.
Also such connection might be disconnected for a while e.g. moving away from Wi-Fi zone and then some messages which had to send through that connection may be lost so that a way to recover such messages is required e.g. here is some messages you couldn't receive.
Therefore, you need a reliable framework to write such real-time web application. Here's features which are required to write a real-time web application I think. (It's called Cettia and I'm the author of that project. As it doesn't provide iOS client, it's not right choice for you here. Just focus on features and roadmap to see what features you may be needed and evaluate a framework you will choose based on them.)
On Node.js world, socket.io framework has a great community so I'm sure someone already wrote iOS client for socket.io. Anyway, make sure that the framework you finally chose has features you need to write your real-time webapp.

What technology do apps use for real time syncing of data?

A lot of apps such as Uber, Lyft, and GroupMe seem like they have real-time data getting pushed down from the server. Obviously they could be faking it by refreshing every n seconds. Another thought was that they could be opening TCP sockets? Or potentially other technologies that I am unaware of.
If programming an iOS app what is the industry standard for syncing data between the client and the server in real time, without user interaction such as swiping up?
WebSockets or polling are the general solutions. Push Notifications can also be used to trigger a poll in some cases.
In addition to Neal's answer, check out the Rocket technique, which "leverages web standards like Server-Sent Events and JSON Patch."
AFRocketClient uses AFNetworking to support this on iOS/Mac, as long as the server supports these technologies.

Large number of WebSocket connections

I am writing an application that keeps track of content pushed around between users of a certain task. I am thinking of using WebSockets to send down new content as they are available to all users who are currently using the app for that given task.
I am writing this on Rails and the client side app is on iOS (probably going to be in Android too). I'm afraid that this WebSocket solution might not scale well. I am after some advice and things to consider while making the decision to go with WebSockets vs. some kind of polling solution.
Would Ruby on Rails servers (like Heroku) support large number of WebSockets open at the same time? Let's say a million connections for argument sake. Any material anyone can provide me of such stuff?
Would it cost a lot more on server hosting if I architect it this way?
Is it even possible to maintain millions of WebSockets simultaneously? I feel like this may not be the best design decision.
This is my first try at a proper Rails API. Any advice is greatly appreciated. Thx.
Million connections over WebSockets, using Ruby, I can't see its real if you not using clustering to spread connections between different instances to handle all the data processing.
The problem here is serializing and deserializing data.
As well you have to research of how often you will need to pull data to client from server, and if it worth to have just periodical checks using AJAX, then handling connection for whole time. Because if you do handle connection and then you not using it - it is waste of resources. WebSockets are build on top of TCP layer, and all connections are not "cheap" as well going through for OS and asking them for data available again is not the simple process, with millions connections it is something really almost impossible without using most advanced technologies in the world.
I head that Erlang is able to handle millions of connections, but I don't have details over it. As well connection is one thing, another is processing data and interaction between connections - this you might want to check, because if you have heavy processing algorithms, then you definitely need to look into horizontal scaling options over clustering solutions.
If you are implementing chat, use websockets.
If you are implementing 1 way messages in realtime use server sent events.
If you are implementing 1 way messages sent every few hours or so, use APNS.
The saying goes phone in hand, use websockets / server sent events.
Phone in pocket, use APNS.
APNS will alleviate wifi dips, tcp/ip socket hangs and many other issues. Really useful. There is the chance that it may take a little time to get through. But then again, there is the chance that websockets will take
Recent versions of iOS let you send APNS to the client without a popup message to the client so it can ask the server for more information. That along with some backgrounding implementations really improves things.
If possible, do not implement totally anonymous clients. It is very tricky to detect if a client reinstalls the app. So you'll end up sending duplicates to the client. Need to take that into account.
APNS looks trivial to implement in ruby, but I'd suggest avoiding the urge and going to using an existing gem/service out there that supports both google and apple. It is much trickier to implement than it may seem at first.
If you decide to stick with websockets, it may make sense to just leverage websockets in nginx like https://github.com/wandenberg/nginx-push-stream-module
ASIDE:
Using SMS where speed is critical is very expensive. $1/month per phone number only sends a max rate of 1 message per second. So sending 100 messages per second = $100/month plus message fees. Do note that 100 messages at a rate of 50 messages/second = $50/month. But if you want to send 1k messages, that takes 20 seconds.
Good luck

Is it possible to build a web-based chat client without a socket-based framework?

I have heard that web-based chat clients tend to use networking frameworks such as the twisted framework.
But would it be possible to build a web-based chat client without a networking framework - using only ajax connections?
I would like to build a session-based one-to-one web chat client that uses sessions to indicate when a chat has ended. Would this be possible in Rails using only ajax and without a networking framework?
What effect does it have to use a networking framework and what impact would it have on my app to not use one? Also any general recommendations for approaching this project would be appreciated.
If i understand you correctly, you want to have to clients connect to you server and send messaged to each other to each other through ajax, via the server.
This is possible, there are two approaches to do this.
The easy approach is to have both client poll every few seconds to check for new messages posted by the other. Drawback is that the messages are not instantly delivered. I think this is an example found in the rails book.
The more complex approach is to keep an open connection and sent the messages to the client as soon as they are received by the server. To do this you can use something like Juggernaut
I would like to add that though the latter works, it is not something http was meant for and it a bit of hack, but hey, whatever gets the job done. A working example of this is the rails chat project which uses a juggernaut derivative.
Technically speaking every network based application has a networking framework under it and, therefore, is socket based...
The only real question here is whether you want to have all that chatter go through your server or allow point to point communication. If the former, you can use the ajax framework to talk to your web server. This means that all of your clients will be constantly polling the web server for updates.
If the later, then you have to allow direct tcp connections between the two clients and need to get a little closer to the metal so to speak.
So, ask yourself this: Do you want to pay for the traffic costs AND have potential liability over divulging whatever it is that people might be typing into their client; or, would you rather just build a chat program that people can use to talk to each other?
Of course, before even going that far, do you really want to build yet another chat client? That space is already pretty crowded.

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