Approach to large object transfers in web services

Question

I have to implement a SOA solution with web services. I have to transfer large objects (ex: Invoices of 25~30mb of XML data) and I wonder what's the best approach...

Should I:

A. transfer parts of this objects separately (ex: header first, then items one by one, regardless of the fact that there could be 1000 of them) in several WS calls and then organize them in "server side" dealing with retries and errors.

Or ...

B. Should I transfer the entire payload in one single call and try to optimize it (and not to "burn" Http connections)?

I'm using .Net's WCF to expose services layer. I accept recommended readings and considerations.

Answer 1

The idea would be to maximize the load and minimize the number of calls. This isn't always simple since - in a one shot call - firewalls or the web service itself could limit the payload size and your message might not make it, or - in case of multiple calls - as you mentioned yourself, you have to deal with errors and retries (basically doing WS-ReliableMessaging).

So perhaps, instead of concentrating on the message of an usual call, you might try changing how you perform the respective call, and maybe have a look at MTOM (Message Transmission Optimization Mechanism) with WCF, or maybe use streaming.