Quoting [Michel Drescher] (Feb 10 2007):
Hi Andre,
Andre Merzky wrote:
[...]
All implementations of this specification SHOULD implement the following Partial File Transfer ERET module:
ERET <SP> PFT="<offset>,<length>" <filename>
offset::= string representation of a positive 64 bit integer length::= string representation of a positive 64 bit integer
Note that the offset specified here is the offset in the file and is not related to the offset specified in the MODE E header, which is the offset in the transfer over the wire.
Saw this for the first time.
But even so, this is an *optional* feature, something we cannot rely on. In HTTP for example, partial data transfer is a MUST, so it is feasible to define a profile for HTTP as each compliant implementation will offer that feature.
What sense does it make to define a rendering for a feature that is optional in the underlying transport protocol?
Yes, I agree, that is a definite problem. However, if I am not mistaken, all gridftp implementations implement partial file transfer. Also, gridftp has a number of advantages over HTTP IMHO: comes with globus and other middleware, and is nicely (ahem) integrated into the security infrastructure. Anyway, I am not sure if that justifies spec dependencies... Cheers, Andre.
Cheers, Michel
-- "So much time, so little to do..." -- Garfield