Dave, Interesting point. The idea of putting a "future work" note in the architecture document for sessions makes sense. In fact, if we do that we should consider just adding a "Future Work" section and fill it with 1-2 lines about each open area we feel that we should address. Here is another thought on the ByteIO question. Let's think about DMI. If you think about what a DMI factory does, it ends up creating a transfer object which really embodies a transfer session. So, why couldn't a ByteIO aware data service participate as the Source in a DMI transfer? If it did that, then the extension to ByteIO would be to add a TransferObject to the Get operation. The effect would be for the source to pump out the specified data over the transfer protocol that DMI negotiated. This leverages DMI and is a simple extension to the ByteIO specification. I suspect that one would have to add an additional operation to ByteIO to allow the client to indicate that the last data has been denoted, thus causing the Source to declare "end of file" to the Sink. Allen Luniewski IBM Cross Brand Services IBM Silicon Valley Laboratory 555 Bailey Ave. San Jose, CA 95141 408-463-2255 408-930-1844 (mobile) "Dave Berry" <daveb@nesc.ac.uk> Sent by: ogsa-d-wg-bounces@ogf.org 05/11/2007 02:12 PM To <ogsa-d-wg@ggf.org> cc Subject [OGSA-D-WG] ByteIO and transport protocols One conversation at OGF20 raised the question of how ByteIO can be used with transport protocols other than those that return data in the response message. The ByteIO spec deliberately leaves this as an extensibility option without specifying how it should be done. It seems to me that it would be too expensive to negotiate a protocol and appropriate mechanism for each request in a multi-request activity. A more practical solution would be to establish some sort of session and then have the ByteIO operations control the transfer across that session. I wonder whether we should mention this possibility in the architecture document? We have deliberately declared session management to be out of scope and I am not suggesting that we go into details, but we could note this as an area for future work. Best wishes, Dave Berry Research Manager, National e-Science Centre 15 South College Street, Edinburgh, EH8 9AA Tel: +44 131 651 4039 -- ogsa-d-wg mailing list ogsa-d-wg@ogf.org http://www.ogf.org/mailman/listinfo/ogsa-d-wg