Subject: Re: draft-zeilenga-ldup-harmful-00.txt

From: "Kurt D. Zeilenga" <[email-masked]>
Date: Tue, 06 May 2003 08:03:48 -0700

At 07:32 AM 5/6/2003, John McGarvey wrote:
>IMHO, this draft takes a very extreme position, stated here:

This draft only reiterates the position which RFC 2251 and
X.501(93) took, and which LDAPBIS is presently taking.  LDUP
takes an extreme position that an extension to LDAP can alter
the LDAP service model in ways which effect implementations
not supporting the extension.  Such proposals should not be
treated as extensions, but as NEW protocols.

Kurt

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From: [email-masked] (Mark C Smith)
Date: Tue, 06 May 2003 12:47:05 -0400

> treated as extensions, but as NEW protocols.

I disagree. And like John, I also disagree with this text from 
draft-zeilenga-ldup-harmful-00.txt:

   The X.500/LDAP information and service models does not support
   multi-master replication and cannot be altered to support multi-master
   replication without causing great harm.

I do think it would be worthwhile for the LDUP documents to address the 
scenarios you spell out in your -harmful draft. John suggested some 
possible solutions, all of which have likely been used in one or more of 
the existing, widely deployed LDAP implementations that happen to 
support multimaster replication (MMR).

The fact is, there is a lot of demand from customers/deployers for MMR. 
If the IETF does not define anything in this area, then the directory 
community will continue to have no common specification for MMR. And 
that will likely cause great harm to LDAP's future.

-Mark Smith
  Netscape

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From: "Kurt D. Zeilenga" <[email-masked]>
Date: Tue, 06 May 2003 10:05:10 -0700

At 09:47 AM 5/6/2003, Mark C Smith wrote:
>I disagree. And like John, I also disagree with this text from draft-zeilenga-ldup-harmful-00.txt:
>

CI assume you are disagreeing with the latter portion of sentence
as clearly the X.500/LDAP information and service models do not
support multi-master replication.

John suggests changing the service model.  I argue that this will
cause great harm.  It certainly will break any application which
relies on this aspect of the LDAP/X.500 service model.

>I do think it would be worthwhile for the LDUP documents to address the scenarios you spell out in your -harmful draft. John suggested some possible solutions, all of which have likely been used in one or more of the existing, widely deployed LDAP implementations that happen to support multimaster replication (MMR).

Again, John suggests changing the LDAP service model.  That, I believe,
is beyond the scope of an LDAP extension and can only be done through
revision of the LDAP "core" technical specification.

>The fact is, there is a lot of demand from customers/deployers for MMR.

There is lots of customer demand to maintain the current
LDAP service model.  There is also significant demand to
expand that model to support LDAP Transactions.

While I generally support extending LDAP to support new
demands, I do not support doing so at the expense of those
who rely on LDAP being implemented as currently specified.

>If the IETF does not define anything in this area, then the directory community will continue to have no common specification for MMR. 

The IETF is not likely to define anything in this area that is
workable.

>And that will likely cause great harm to LDAP's future.

LDAP is what it is.  If the demands are not met by the current
specification and cannot be met through appropriate extensions,
then it's time to design a new protocol (LDAPv4?) with a
service model that meets those demands.

Kurt

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From: [email-masked] (Mark C Smith)
Date: Tue, 06 May 2003 14:01:59 -0400

> support multi-master replication.

Yes, although I would say that the X.500/LDAP information and service 
models to have have explicit support for MMR.

> relies on this aspect of the LDAP/X.500 service model.

I believe it is inevitable that there will be some pain associated with 
certain kinds of LDAP extensions (MMR, transactional support, etc.) But 
I think the pain is worth bearing in some cases in order to progress the 
state of the art.

-Mark

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From: "Kurt D. Zeilenga" <[email-masked]>
Date: Tue, 06 May 2003 12:15:04 -0700

At 11:01 AM 5/6/2003, Mark C Smith wrote:
>I believe it is inevitable that there will be some pain associated with certain kinds of LDAP extensions (MMR, transactional support, etc.) But I think the pain is worth bearing in some cases in order to progress the state of the art. 

There are certainly works which propose changes to the LDAP
Models under the guise of an LDAP extension.  However, I think
we should lift this guise from all such proposals and treat
them not as extension proposals but as protocol revision proposals.

Kurt