I am going to design a notification service which is supposed to do the following:
Clients call notification service at startup with initial data (client ip, client id).
The server saves clients in connected clients list using their IPs.
If one client needs to notify (send message to) other clients, it calls a method on the notification service to publish this message to other clients using their IPs.
On client shutdown, the service removes this client from connected clients list.
My Question is:
1- Is this an applicable design for such a notification service?
2- I know that connections between service and client can be implemented using WCF callbacks, Microsoft Message Queue and Sockets. Is there any other technology / method that can be used in c#?
Note:
Now, clients are .net c# applications, but in the future clients may contain mobile applications, so i need a method that is platform independent.
Thank you
Related
I'm trying to implement an application server just like a chat server using rabbitMq.
Clients connect directly to the rabbit server. the application server should be able to know which clients have been connected and when a client disconnects an event should be fired in the application server.
Is it possible to implement this kind of functionality with Rabbitmq?
Does Rabbitmq have any kind of event dispatching for connection events?(not for clients but for my application server)
I'm using official C# client for Rabbitmq.
As #Lutz Horn already said, you can use the event exchange plugin to emit events related to connections, channels and much more.
Reference: https://www.rabbitmq.com/event-exchange.html
GitHub: https://github.com/rabbitmq/rabbitmq-event-exchange
You have to create a queue, so that the event exchange routes these events to this queue. And have a consumer that listens to this queue. I have added a link to the one that I am using.
Code: https://gist.github.com/sathishbabu96/35821a6b1e90daa76d3dd76bef084788
I am creating a client application that downloads and displays market data from Yahoo! for a university project, but that also sends out notifications to mobiles (so far using Google cloud messaging). So far it's a WPF client and the "server" is a class library - so far working. What I was wondering, is can you mix this server with a WCF service - the WCF service I was planning on using for registering devices, as well as accepting and parsing commands.
So I would call .Start() on my server object, and it will be constantly running in the background, while a WCF REST service runs alongside it - or would I be better simply having a thread running on the server that can accept input... sorry if this is confusing, but just wondering if it can, or has been done before or any advice. :)
Just to explain a bit better
The client front end and the "server" are running on the same machine - I was calling it a server because it is not only updating the front end, but sending out GCM notifications at the same time. I was wondering if maybe a WCF service could be added to make it simpler to handle adding devices to a database ("server" reads a list of device reg ids from a database, sends notifications to these) by allowing an android app to details via REST or something similiar
I would explore wrapping the class library in a Windows Service (which is essentially a process that runs continuously, and can be stopped/started/paused) and keep your WCF service as a web service for client communication.
How the WCF client service communicates with the Windows service is up to you - whether you store the data in a shared database, keep it in memory and have another WCF layer communicating between the two, etc. A shared database would be the most straightforward, especially if you want to persist the data for use by other apps/services as well.
WCF Service would be useful if you had one notification service on your server with multiple WPF client application connecting to it. If you have just one application running on the same server then not sure if it will be worth the overhead.
The usual pattern is to host WCF service in IIS, that way it always starts whenever first request is received. WCF is very flexible though, therefore you can host in in Windows Service, Console Application, etc.
I am trying to write a monitoring tool to monitor some information
It will gonna work on azure normally. So i gonna host the database on azure also the webservice will be hosted at azure.
On the client's i read from the config file how many time's he need to update the information to the azure database ( with the webservice on azure ).
Now i want to send also some commands to the client itself. Like start service, .... what is the best way to do that?
How can i send it from a website that is hosted on the azure platform?
I think you should consider implementing a WCF service at the client as well. The Azure side of your software could call operations from this service when it needs to instruct the client to do something.
The WCF service at the client should be something simple,hosted in a Windows Service or in your actual client (whatever it is... win forms, console, etc).
Since you have no VPN, it sounds like you may have a problem with hosting a WCF service on the client. If the client is behind a firewall, you would have to modify the firewall configuration to allow your server to connect to this service.
Last time I had to do a service like this, I used Comet. The server maintains a queue of messages to be sent to the client. Your client connects to the web service and requests any available messages. If messages are available, the server returns them. If not, the server leaves the request open for some time. As soon as a message arrives, the server sends it down the already-open connection. The client will either periodically time out/reconnect or send a keep-alive message (perhaps once per minute) in order to keep the connection alive in the intervening firewalls.
We want to implement a client server application. here is the scenario.
Server listens for client 24/7.
Server accept request for client and save it in DB for further process.
Once processing is done (it may take few hours), Server will response back to client.
in short , client and server listens for each other 24/7.
I want to implement it in C# but i also want that it should be accessibly from all platforms.
Also is it possible in WCF?
I agree with Yuck, this is a basic WCF scenario. There a few articles, videos and tutorials to get you started here http://msdn.microsoft.com/en-us/netframework/dd939784
We are using WCF Services that transfer some data from a Client Application to the Server Application (WCF Service). This last one will apply an algorithm using these data and send back the result to the client.
We would like to authenticate the Client Application from the Server WCF Service. Would it be possible to get the Client Application Checksum directly from the WCF Service?
We are already using wsHttpBinding but we would like to add one more layer on the client application integrity.
Appreciate for your help,
Camille.
he WCF service can't get anything from the client unless the client sends it to the service. So if you can get your client to send your service the checksum (as a method parameter), then you're in business. WCF is not magic. Nor is any "service" technology for that matter. It is a simple tcp/ip communication between a client and a server. On both side, the only information that goes across is the information each side decides to send, nothing more.