[BYTEIO-WG] Notes from the OGSA ByteIO session at OGF19

[Andre Merzky]

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