We can use the survey to find out about updates from some source, for example, clients connected to a web server. WCF provides an excellent opportunity for duplex contracts in which I can maintain a connection to the client and make calls on this connection as I see fit. Some of them looked at the merits of both solutions, and I wanted to get feedback on when to use each strategy best.
I would use an event-based mechanism instead of polling. In WCF, you can do this easily by following the Publish-Subscribe framework Juval Lowy provides on its website, IDesign.net .
Partly depends on how many users you have.
Say that you have 1,000,000 users, you will have problems saving many sessions.
But if your system can respond to 1000 polling requests per second, each client can poll every 1000 seconds.
I think Shiraz nailed it, but I wanted to say two more things.
If this makes sense for your solution (this applies only in certain situations), the MSMQ binding allows the client to send data to the service in asynchronous mode (for example, duplex), but the service is not a “poll” for messages ... it receives a notification, when one enters the line through some under coverslip fixtures.
This method forces you to communicate (the client becomes a server, the server becomes a client), but if most messages are one-way, this would provide many advantages. Another advantage here is obviously a communication queue - the server may be down and not miss any messages ... it will pick them up when it returns to the Internet.
Something to think about.