Streaming an undetermined number of objects through WCF

Question

I have a WCF service that needs to read large (10 to 20 million) numbers of objects from the database.

What I'd like to do, is have the client open up a stream and have the server push data from the database as it's reading.

So the client could just sit in a loop deserializing messages until it gets the EOF message from the server, in the style of the Twitter Streaming API, but with a finite set. The issue I'm having, is how to return the stream and then keep writing to it. Is this possible with WCF?

Answer 1

How about instead of setting up a streaming/blocking service you use something like WS Dual Http. With it you have an async bidirectional callback channel that allows you to request/reply information back and forth between the server and the client. Issues you may see if you want to stream the entire set is a normal fashion is that some of the resources may block other requests (or timeout) while other users try to access the service.