[ogsa-naming-wg] GGF/OGSA standards for hierarchical namespaces

[David Snelling]

Folks,

This mail may bounce off some of these lists, but I hope everybody sees 
it if they are interested.

It sounds like a re-factoring of RNS along the lines discussed  is the 
best way forward. Is the a group of people willing to do a VERY ROUGH 
straw man decomposition of the current spec?



On 28 Mar 2006, at 2:28, Christopher Jordan wrote:

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> All,
>
> Forgive the wide distribution on this e-mail, but this issue seems to 
> be to be both extraordinarily important to the future of GGF/OGSA 
> standards efforts and also in a state of either limbo or paralysis. 
> The topic I'm addressing here, both in my capacity as the secretary of 
> GFS-WG and as a generally interested participant on a few different 
> GGF working groups, is the question of adopting a single, possibly 
> minimal, standard for creating hierarchically organized collections of 
> pointers (WS-Names? GSR/GSHs, to date myself?) to  "resources", where 
> the term "resource" could denote a service providing access to a 
> collection of files, computational resources, or database records 
> (that's a non-exclusive list), and where some items in the hierarchy 
> could actually represent directory-like structures, i.e. containers 
> for other collections of resources.
>
> The way I got involved in this discussion through the Grid File 
> Systems-WG, which at the time was bringing the RNS specification 
> forward for final approval as a GFD. Subsequently, there have been 
> numerous discussions outside of the GFS-WG context about the 
> suitability of the RNS standard for more general applications, as well 
> as the (perceived) complexity of the standard as a barrier to entry. 
> There have also been alternative directory construction standards 
> proposed by members of the OGSA-Naming-WG.
>
> The following are the activities/proposals I know of:
>
> RNS: I know the GGF editors have returned the final(?) RNS draft to 
> GFS-WG, with the suggestion that it is too specific to filesystem 
> needs, and the suggestion that it either be limited in scope to GFS 
> applications only (a non-optimal solution for obvious reasons) or that 
> the authors work with the OGSA-Naming people to help develop a 
> universal standard for hierarchical resource namespaces. If we are to 
> move forward with RNS, one of these options will clearly be a 
> necessity, given the points Greg Newby made in his responses on behalf 
> of the GFSG.
>
> WS-Directory: This is the hierarchical namespace standard developed at 
> UVa in response to their difficulty in implementing the complexities 
> and ambiguities in RNS. I like the simplicity of WS-Directory, however 
> it seems to be missing significant requirements for general use such 
> as attributes, both attributed which should be required such as 
> time-to-live, and the ability to add extensibility attributes such as 
> resource type, QoS, etc. This ability to add arbitrary attributes is 
> present in RNS but it still lacks some obviously fundamental required 
> attributes.
>
> Finally, Dave Berry sent an e-mail immediately after GGF16 in which he 
> mentioned the suggestion that we separate this functionality into two 
> logical functions, and therefore standards - a Directory Interface and 
> an Iterator interface, in which Directory interfaces were essentially 
> just pointers to Iterators, which would be standardized. However, 
> there would be no restriction that a Directory point to a particular 
> type of iterator interface. One point I wasn't clear on from the 
> e-mail was whether an entry in an interator could be another 
> directory, although I suspect it can.
>
> This short list is what I've got within easy reach. As I said 
> previously, I believe this is an important issue to resolve quickly, 
> and I'm sending this note in the hopes of initiating the conversation 
> among as many of the relevant parties as I can. Please feel free to 
> forward at will, respond with agreement, anger, or even unconcealed 
> rage.
>
> Possible ways forward would be for us to have a conference call 
> (GFS-WG meets rarely, and we could quite easily give up our call for a 
> more focused discussion of these issues), an extended e-mail 
> discussion, or a meeting at the next GGF (assuming we get a chance).
>
> Let me know how you feel about the options presented above, or feel 
> free to propose new ones if you like. The important thing is that we 
> begin to gain momentum, and then keep it going forward.
>
> Thanks.
>
> N.B. For anyone who may have missed any of the discussions reference 
> above, please let me know and I'll be happy to forward them to you 
> from my archives.
>
> - ----------------------------------------------------
> Chris Jordan
> HPC Systems Engineer
> High End Computing Systems Group
> San Diego Supercomputer Center
> ctjordan at sdsc.edu
> 858.534.8347
>
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-- 

Take care:

     Dr. David Snelling < David . Snelling . UK . Fujitsu . com >
     Fujitsu Laboratories of Europe
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