Leandro, > Thanks for your help. Reading my last post again I think I wasn't clear > enough.
That's OK, it's part of thinking about the problem and working out the best solution. > My server will handle TWO different types of clients: > > 1) small network devices (via UDP) > 2) desktop applications (possibly using hessian) So small network devices are broadcasting events to mulitple clients? If so, are the desktop clients on the same subnet as the small devices? In that case you could bypass the server and multicast directly to the desktops. If not, you will have to use the server effectively as a relay. > > The server has to publish the events created on the network enabled devices > to all desktop clients that subscribed to the correct type of event. > > I guess you thought that I was trying to use hessian for #1, not #2. > I never used hessian before. I would be really nice to have a > small/efficient protocol handler to send and receive messages back and forth > (server and client #2). I'm not sure if hessian is the way to go. Maybe a > plain tcp socket would be better to push events from the sever to desktop > clients. I think you've go to back and be clear in your mind what Hessian actually is, because it is not a network protocol. Hessian is a binary data binding protocol that defines a language neutral wire format for transporting application level data structures. The problem that Hessian solves is dealing with data marshalling and unmarshalling over the wire in a compact and language fashion. Nothing more, nothing less. Hessian assumes nothing about the underlying transport mechanism, so how you do the IO is totally up to you. So Hessian can work with raw TCP sockets, HTTP, Servlets (which is an API not a protocol), UDP (if you deal with the framing), basically any transport that can encapsulate opaque binary data. For example, you can encode application layer data in messages using protocols such as AMQP (or probably any other MOM API) or an API such as JMS. Given your problem, I would not be primarily worried about the data binding layer first, I would sort out the data transport first. For example, what physical transport are you going to use to have the desktops subscribe to your server? Are you going to poll the server in a request/response fashion, open up a socket listener on each desktop or are you going to use a messaging solution? Then if you can't multicast, why are you using UDP in the first place? If you are just using it as a single unidirectional channel, you will still have to deal with framing, acks, dropped datagrams and duplicate deliveries, so add the overhead of TCP into the application layer and have re-invented the wheel. So I would worry about the transport first, knowing that whatever I choose, Hessian is simple and powerful enough to encode/decode data onto/from the wire. HTH, Ben _______________________________________________ hessian-interest mailing list [email protected] http://maillist.caucho.com/mailman/listinfo/hessian-interest
