SOAP or REST suitable for non-query-response communication?

Question

We are building a proprietary system involving a client and a server linked over TCP/IP. Occasionally, the server will have some new expected or unexpected information that would be of interest to the client. My understanding is that SOAP and REST are query/response systems that require the client to request something and the server responds back. We need the client to register and the server to respond back if and when the new information is available. Are these protocols capable of such behavior? In addition, we need standard database-like queries requiring immediate response.

Answer 1

First, REST isn't a protocol, it's more of an architecture style.

Second, neither of these are designed for push data delivery.

You could use either for the query-type messages, but you'll need to devise an out-of-band communication protocol to use for push notifications. If your data is fairly simple you could just use a basic TCP socket.

Answer 2

If you are in the Microsoft world, take a look at WCF, it is capable of this type of communication.

Whether you are in the Microsoft world or not, I would suggest looking into XMPP and AMQP.