Question

I’m working with an n-Tier application using WinForm and WCF

Engine Service (Windows Service) => WCF Service => Windows Form Client Application

The problem is that the WinForm Client Application need to be 100% available for work even if Engine Service is down.

So how can I make a disconnected architecture in order to make my winform application always available ?

Thanks.

Answer 1

Typically you implement a queue that’s internal to your application.

The queue will forward the requests to the web service. In the event the web service is down, it stays queued. The queue mechanism should check every so often to see if the web service is alive, and when it is then forward everything it has stored up.

Alternatively, you can go direct to the web service, then simply post it to the queue in the event of initial failure. However, the queue will still need to check on the web service every so often.

EDIT: Just to clarify, yes all of the business logic would need to be available client side. Otherwise you would need to provide a ‘verify’ mechanism when the client connects back up.

However, this isn’t a bad thing. As you should be placing the business logic in it’s own assembly(ies) anyway.