[ogsa-naming-wg] Iterators and Directories

[Dave Berry]

There is a suggestion in the air that the RNS spec should be split into
three: a Directory interface, an Iterator interface, and a logical name
resolver.  This raises the question of how the Directory interface
should refer to the Iterator interface, especially as down the line we
might want to use a different Iterator interface.  An Iterator interface
is important, because directories may have hundreds of thousands of
entries.
 
WS-DAI has a pattern that can help here (and perhaps elsewhere in the
architecture).  It specifies two patterns for data access: direct and
indirect.  Direct access returns a result in the response message.
Indirect access returns an EPR that the client can use to access the
result, via an appropriate interface (such as an iterator).  The
indirect access request message includes an optional QName that
specifies the interface that client will use to access the result.  
 
This pattern would allow the Directory spec to be independent of any
particular Iterator interface.  Actual implementations could support
whichever iterator interface is appropriate.  They could provide
multiple interfaces if they wish.  The interfaces don't even have to be
iterators, if someone can think of other interfaces that will be useful.
The available interfaces are specified via a property of the service.
 
I propose that a similar operation is included as an optional operation
of the Directory sub-part of RNS.
 
Dave Berry
Research Manager, National e-Science Centre
15 South College Street, Edinburgh, EH8 9AA
Tel: +44 131 651 4039
 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.ogf.org/pipermail/ogsa-naming-wg/attachments/20060214/5bc821ff/attachment.html