I am using Smack library on android for implementing xmpp based chat. How much time does ejabberd server takes to mark a user offline (start storing into offline storage) if it receives a presence type=unavailable from a client.
Is it instant or does it takes some time?
The presence is broadcasted in realtime, so yes, broadcasting presence unavailable is instant.
Related
I want to have my application receive notifications without forcing the user to be logged in or authenticated. Thank you for your time!
Well, I'm using OneSignal to send notificaitions to the users of my Android app and it's working fine. Moreover, it uses FCM as its base. So, that shouldn't be a problem too. You can segment users thet way you want and send notifications to one or many - upto you. It's all for free and very easy to set up the basics of it. It's here: OneSignal
You can probably use Socket IO for your case to send messages from one device to another.
There are many good to have Socket IO frameworks which can consider for your requirement
Signal R in Android
SignalR is a new library used to add real-time web functionality to your applications. Signal R uses technology such as
web sockets
Event Source,
forever frame
long polling
Signal R is capable of selecting the best from those four technology depending on your internet connection and your application stability.
Signal R is used in application such as
Chatting application
Stock market application
Real-time gaming
Native Socket.IO
Socket.IO provides an event-oriented API that works across all networks, devices and browsers. Its incredibly robust (works even behind corporate proxies!) and highly performant, which is very suitable for multiplayer games or realtime communication.
I am currently writing an iPhone application that sends and receives JSON data from a remote server to essentially display realtime information. Me and my partner started the project using Google App Engine (Python) for the server-side implementation mostly because it was easy to pick up and seemed suitable for our needs at the time. However, we're only just now starting to see the downsides of the framework for realtime iPhone apps - APNS is not at all supported, and neither is the GAE Channels API. So our only option for displaying the realtime server data on our app is to continuously poll the server, which certainly seems like horrible design.
We'll have to port our server-side code to a new framework. My question is, which one do we use? From numerous searches, I still have yet to find a satisfactory answer.
I should mention that I don't necessarily want the server to send push notifications. I just want to be able to push data to clients in real-time, and then manipulate that data on the iPhone client-side code. We're fine with setting up the framework on a local server if we have to.
Since you don't want to be pull data in background (lett alone if it is even possible)will have to use APNS.
But why switch away from google app angine, you could use an APNS provider like Urban Airship wich provide there on API to connect with.
You'r not even the fist to run into this problem: Apple Push Notifications on Google Appengine
Probably the easiest realtime framework you can use for sending data to iOS clients in real-time is PubNub (http://www.pubnub.com). It's reasonably priced, and it scales to anything you can throw at it. In my experience, it has no problem delivering a message to an end client in under .25 milliseconds (regardless of the number of clients it's being sent to).
Their latest version also supports APNS functionality for when you app isn't in the foreground.
https://github.com/pubnub/objective-c/blob/master/iOS/README_FOR_APNS.md
If you want to create your own APNS server (since you are running on App Engine anyway), there are examples of how to do that using App Engine's new Socket API. I've written a demo python AppEngine application that people might find helpful in this regard.
https://github.com/GarettRogers/appengine-apns-gcm
I'm planning to setup some sensors for a project I am working on. I plan to use a simple xmpp client on each device hosting sensors and posting the readings via PEP/PubSub.
I would like to run a program which dynamically displays this sensor data upon receiving the push notifications from the sensor clients.
I intend to communicate on a LAN with 100Mbs connections and several WIFI APs as needed for the sensor locations.
Is XMPP a good choice for a backend?
Would this scale well at say 100 devices running 6-24 sensors each updating every 15-30 seconds?
XMPP would certainly be able to handle this use case, and seems a good fit based on the small set of requirements you have shown. I am assuming that the sensor data is small amounts of textual information.
From what I can see, I would not use PEP though, just straight up pubsub with a single node for all the sensors to publish to. Pretty much as simple as it gets.
I would think that any XMPP server should be able to easily handle that load. I know I was able to publish 800,000-1,000,000 items to a persistent node in Openfire in about 5 minutes (3.7.2 alpha version). A non persistent node would probably do a little better.
From my understanding you cannot socket a connection between two iPhones (correct me if I'm wrong). So what I would like to do is have one server sitting between the client application that accepts messages and redistributes them to the appropriate person(s). Essentially the application is going to allow people to have a shared map that has their locations and everyone can annotate it.
1) I have been reading and researching into the CFStream class, but I'm curious to know if it might be better to just use the C send() and recv() functions. They almost seem much easier to use. What does CFStream offer over the native C socket functions that make it a better option?
2) Since I need the phone to actively listen for updated shared user locations/new annotations from other users, my plan was to periodically have the phone poll the server for any "news" from other users (say every minute or two). Is there anyway the phone could spin off a new thread in the application that is constantly waiting for incoming traffic? It would make life easier to be able to have a user annotate the map, push that to the server which then immediately updates the appropriate users maps.
I have been using example socket code from Jonathan Zdziarski's iPhone SDK book from O'Rielly Media to just try sending messages between a server and iPhone emulator (the classic knock knock joke server/client). However, after sending 1 or 2 messages the server gets stuck "receiving." The code runs perfectly when not sent from an emulator, as I can seemly spam the client send function and get a response from the server each time. Could the server be hanging because I use send() and recv() instead of the CFRead and Write stream?
You can socket iPhone applications using bonjour, or even GameKit (which is what I use because it manages all data for you).
It is very usual that an iPhone send data to internet server.
But what if a server wants to connect to an iphone?
I have wondered long about it.
For example, like many web-based apps like Facebook, what is the mechanism/algorithm behind, so that when, for example, any updates on your wall can be noticed to you in a real-time manner?
Hope some can understand my query.
Have a look at this Wikpedia article about Push Technology.
Push technology, or server push, describes a style of Internet-based communication where the request for a given transaction is initiated by the publisher or central server. It is contrasted with pull technology, where the request for the transmission of information is initiated by the receiver or client.
Your iPhone could intermittently 'poll' the server, looking for any data it needs to be sent. Say every 5 seconds, or after some trigger - it would call the server and ask for new data.
You could use push technology: i.e. have a continuous http connection open to your server that allows data to be sent both ways. LightStreamer is a product that does this that i've used before. This is the most elegant and efficient solution for streaming data.
You could use iOS push notifications. The server can trigger a push message and target it at a specific device and send your iPhone something...
Push notifications are the way to go with iOS. I have used push notifications through the cloud-based Cocoafish backend server. This is a great solution as you can 'subscribe' mobile devices to a push notifications channel - for example, a channel for friends requests or a channel for chat etc. Its real easy to set up with all the correct certification. There's good set up instructions in the documentation on their site too.