protocol buffers and actual transport options - sockets or middleware

I am developing a client/server application for which I am evaluating a few options for the communications layer.

As part of this communication framework, I am contemplating using google's protocol buffer (PB) for representation of the transport data instead of re-inventing my own binary structure.

Now coming on to the actual transport, I am wondering if one should use plain sockets to send/receive these binary messages or use some form of midd开发者_JS百科leware. Using a middleware has certain obvious advantages over sockets. A few that I care about include: communication models - publish/subscribe, request/response and fail over.

On the other hand, using sockets has the advantage of low overhead compared to the middleware approach and will deliver better performance.

One can also think of using the RPC libraries available with protocol buffers (third party add-ons on google's protocol buffer wiki) to communicate between the client and the server. Though it abstracts from the low level socket, it still does not support the middleware features.

At the moment, my client is an Adobe Flex GUI and two server side processes (One java and another C++). In the future, the client and server side can potentially have other services developed in other languages as well such as .NET

What do the experts feel about these choices and from experience what works well without compromising on performance. Are there other alternatives that developers go with?

Thanks Dece

Unless it's a learning exercise, you absolutely, positively must use some middleware. There are lots of choices: AMQP, ZeroMQ, XMPP, Comet/Bayeux.

For your scenario, you probably want something web-based, so XMPP over HTTP may be a good option. However, I'm partial to Comet (though I have found Bayeux to be too complex for my needs).

Which platform?

If Windows then I have a free, simple, high performance, IO completion based pluggable server platform called WASP which is available from here.

Simply write a DLL or two and plug them in and you're done with the networking.

I don't currently have a protocol buffers based plugin example but it's on my list of things to do...