Re: Registration of non-LDAP schemas?

[capple@xxxxxxxxxxxxxxxxxxxxxx (Christopher W Apple)]

>In reading through "Directory Schema Listing Requirements", 
>draft-apple-schema-rqmts-list-03 (currently expired)

The expire date in the document that I sent to the I-D Editor
was May 8, 1998. Are you saying that you can no longer find it
in any of the I-D repositories?

>, I notice that there 
>is an intentional and pervasive bais towards limiting the scope of 
>registration activity to just LDAP schemas.

This is not true. The documents explicitly allow for non-LDAP schemas
to be listed. The document does currently limit schema listed for the
initial deployment of the service to being schema associated
with directory service protocols (LDAP, WHOIS++, RWHOIS, with a request
to add WHOIS).

>  However, there are other 
>Internet groups which are in need of schema registration services, and this 
>need is likely to increase in the future.

True. We are exploring options and modifications to all schema listing
service documents that will allow the initial deployment of the service
to scale towards handling the breadth of schema listing service flavors
that you imply.

Re: your comments on XML/SGML DTDs; we have been discussing this on
the engineering team. Since the need for this one appears to be
rather pressing for a wide community of interest, it may be supported
in the initial release of the schema listing service. But you should
consider that as strictly tentative until such time as the SCHEMA WG
achieves concensus on supporting it.

>This doesn't appear to require a large change to the requirements document. 

You're correct. But the requirements document is not really the issue. Its
all the other documents that require oodles of changes, unless you have
separate listing procedures documents for each protocol/technology/mark-up
language for which you wish to list schema. While, I'm pretty sure that
there is some happy middle ground between having 1 procedures document for
all such schema listing types and having 1 procedures doc for _each_
schema listing type, I'm not sure that anyone has a good answer to where
and how such happiness can be achieved. At least not yet. I think this
evolve over time and that we should not try to come up with a procedures
document overnight that covers every type of schema listing possible.

> Requirements which would require change appear to be:
>
> Meta data element syntax SHALL be defined based on the concept of
> tagged attribute type-value pairs.
>
> Language tags as specified in [RFC1766] MUST be used in listing
> content and meta data.
>
> Meta data element values MUST be encoded using the UCS Transformation
> Format - 8 bit form [RFC2044].
>
>Whether you decide to allow non-LDAP metadata to be registered or not, 
>these particular requirements seem to be far too low-level compared with 
>the other requirements in the document.  The real requirements here seem to 
>be:
>
>Metadata definitions must be consistent with the type of metadata (e.g., 
>a-v pairs for LDAP, DTD for XML, etc.)

I would argue that DTDs for XML schema listings are part of the content
and not of the metadata. Schema listing service metadata is used to catalog 
listings and should not contain information which actually helps to specify
the details of a particular schema. Thus, I think that it is still appropriate
to constrain metadata structure as the requirements document currently does.
But, I confess to not being an expert on DTDs. If my understanding of them
is misguided or mistaken, could someone chime in and explain why XML
listings would need a different metadata structure than any other listings
stored in the repository?

If you were concerned about being able to search through DTDs for tags
or key words, we have added requirements for the repository operator to
provide searching facilities capable of pawing (how's _that_ for a
hi-tech term? :) through listing content.

>Listing of content and metadata must be consistent with the IETF character 
>set policy [Alvestrand, 1998].

I'll take this comment to the engineering team for consideration.

>So, the question I raise is: should non-LDAP schemas be capable of 
>registration and retrieval using the mechanisms defined by this working 
>group?
>
>- Jim

Eventually. The timeframe in which the service is opened up to
non-directory-service schemas is open for debate. The only answer
that is plausible (in the most general sense): not immediately.


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Chris Apple                     Business Site: AnyWho Directory Service
Internet Directory Group                       http://www.anywho.com
AT&T Laboratories
capple@xxxxxxxxxxxxxxxxxxxxxx
+1 908 582 2409                 Tired of slow directories?  Try AnyWho.
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