Subject: LDAP Client Update: consideration of alternative proposals

From: "Kurt D. Zeilenga" <[email-masked]>
Date: Mon, 26 May 2003 08:10:55 -0700

The LDUP WG is chartered to deliver:
  o LDAPv3 Client Update
        A protocol that enables an LDAP client to
        synchronize with the content of a directory
        information tree (DIT) stored by an LDAP server
        and to be notified about the changes to that
        content.

Over the last few years, the WG has engineering a technical
solution for this deliverable.  This solution is specified
in the I-D draft-ietf-ldup-lcup.  Over the last 9 months or
so, Jong and I, acting on an individual basis, engineered
a technical solution for this deliverable.  This solution is
specified in the I-D draft-zeilenga-ldup-sync. 

Each of these technical solutions are intended to fulfill
this deliverable.  I also believe both sets of authors
believe that their approach best fulfills this deliverable.
It is also likely many members of this WG have formed opinions
as to which technical solution best fulfills this deliverable.
However, it is unclear to me whether both I-D, in particular
the most recent revisions of each, have been thoroughly
considered by the WG.

WG I-Ds are implicitly viewed as being under WG consideration
and it hoped that significant number of WG members review the
I-D as it evolves.  Individual I-Ds are not necessarily viewed
as being under WG consideration unless submitted to the WG for
consideration by their authors.  They generally are reviewed by
few WG members until consideration is specifically requested.

I now submit the draft-zeilenga-ldup-sync to the LDUP WG
for consideration as a technical solution to its "LDAP Client
Update" deliverable.  I believe the latest revision,
draft-zeilenga-ldup-sync-02.txt, is suitable for progression.

I ask the WG to view draft-ietf-ldup-lcup and draft-zeilenga-ldup-sync
as technical alternatives and give thorough consideration to both.
It is up to the WG to decide which solution is technically
superior.  As it is the function of the WG Chairs to manage the
group process, I defer procedural questions and issues to Chris
and John.

As the differences between the approaches is fundamental in
their design, it will be difficult to compare them without some
basis to which can be measured against.  It may be appropriate
for the WG to examine what kinds of applications it intends its
deliverable to be applicable to, what the requirements of these
applications are, and how each of the technical alternatives
measures up to these requirements.  The WG should also consider
broader issues, such as chattiness and security considerations.
The WG should consider the appropriateness of the design and
other constraints each places upon implementations.

In regards to the WG milestone:

   May 03    LDAPv3 Client Update Protocol I-D goes
             to WG Last Call as Proposed Standard 

I would like the WG to defer this WG Last Call until it has
thoroughly consider both technical alternatives and reached a
consensus as to which alternative it would like to pursue.
Then that alternative should be prepared of WG Last Call as
the WG's "LDAPv3 Client Update Protocol I-D".  I believe it
necessary to defer the WG Last Call as the WG first needs to
thoroughly consider both alternatives.

I'd like to say a key design difference which is a major factor
in I considering draft-zeilenga-ldup-sync technically superior
to draft-ietf-ldup-lcup.  In attempting to implement
draft-ietf-ldup-lcup, we found that requires server implementations
to maintain complete history information in order to provide
eventually convergent incremental refreshes.  We found that
where the server only maintains simple state indicators such as
timestamps, it cannot generally provide eventually convergent
incremental refreshes.  If the server maintains partial histories,
the server will be limited in cases where it can provide
eventually convergent incremental refreshes.  In October 2002,
the WG consensus was declared on an alternative approach (but
later recanted).  We implemented this approach and found that it
allowed all of the above implementation variants to provide
eventually convergent incremental refreshes.  This was document
in documented in early revisions of draft-zeilenga-ldup-sync.
As a result of WG discussions about this approach, it was noted
that this approach didn't allow servers to take advantage of
histories they maintained.  In our latest revision, we adopted
a hybrid approach which allows servers to take advantage of
histories they maintained.  Hence, I believe draft-zeilenga-ldup-sync
is technical superior in that it does not place significant
implementation constraints in order to support eventually
convergent incremental refreshes while allowing implementations
take advantage of histories they maintain.  There are, of course,
many other factors in my consideration and I am quite willing to
elaborate on these in subsequent discussions.  Before doing so,
I will await direction from the chairs on how to proceed with
the consideration of the alternatives.

Comments?

Regards, Kurt

---

From: "Chris Apple" <[email-masked]>
Date: Tue, 27 May 2003 08:24:37 -0400

WG Members should review the request Kurt has made.

John and I will respond to the list on the procedure
we'll use in considering Kurt's request, and if appropriate,
acting on it.

Kurt,

There are a few major points I'd like to be sure I'm 
summarizing correctly before John and I respond on the
procedural issue. You are requesting the following:

1) that the WG formally consider your individual
   contribution as an alternative to the existing
   WG deliverable for LDAPv3 Client Update Protocol.

2) that the WG evaluate both documents based on
   technical merit.

3) that the WG emerge from that evaluation process
   with a single document that will be processed
   through a WG Last Call and submitted to the Ads
   as the WG deliverable for LDAPv3 Client Update
   Protocol.

4) that the WG Last Call milestone for LCUP be
   rescheduled further out in time to accommodate
   the above.

Did I miss any key points in your request?

Do any of them need clarification?

Chris Apple - Principal Architect

DSI Consulting, Inc.

mailto:[email-masked]

http://www.dsi-consulting.com

-----Original Message-----
From: Kurt D. Zeilenga [mailto:[email-masked]] 
Sent: Monday, May 26, 2003 11:11 AM
To: [email-masked]
Cc: Chris Apple; John Strassner
Subject: LDAP Client Update: consideration of alternative proposals

Comments?

Regards, Kurt

---

From: "Chris Apple" <[email-masked]>
Date: Tue, 27 May 2003 15:05:23 -0400

As WG Co-Chair, I want to be clear with WG Members about
the status of Kurt's request:

1) The WG needs to establish a consensus of support for
   proceeding as Kurt suggests in order for John and I
   to endorse it and make any requests for changes to
   milestone dates or other charter changes to our ADs.

2) It is an open topic for discussion. Specifically, John
   and I need to see comments (preferably with rationale)
   about the value (or lack thereof) of proceeding as
   Kurt suggests. Do not wait for further communication
   from either John, Kurt, or I to start this discussion.
   John and I don't want to have to resort to interpreting
   silence on this issue in one way or another.

   Make your opinions known NOW! This applies to you even
   if you are an author of one of the drafts covered by
   Kurt's request.

3) The milestone date for the WG Last Call for the LCUP
   deliverable is still May 2003 and requires approval
   of our ADs to slip intentionally.

4) John and I will await confirmation/clarification of our
   understanding of Kurt's request from Kurt before making
   the request to our ADs to slip the milestone date to give
   us enough time to consider whether the WG wishes to:

	a) proceed as Kurt suggests
	b) stay with our presently chartered course of action,
	   albeit with some slippage
	c) take another path completely different from those

DSI Consulting, Inc.

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On
Behalf Of Chris Apple
Sent: Tuesday, May 27, 2003 8:25 AM
To: 'Kurt D. Zeilenga'; [email-masked]
Cc: 'John Strassner'
Subject: RE: LDAP Client Update: consideration of alternative proposals

Kurt,

DSI Consulting, Inc.

-----Original Message-----
From: Kurt D. Zeilenga [mailto:[email-masked]] 
Sent: Monday, May 26, 2003 11:11 AM
To: [email-masked]
Cc: Chris Apple; John Strassner
Subject: LDAP Client Update: consideration of alternative proposals

Comments?

Regards, Kurt

---

From: [email-masked] (Mark C Smith)
Date: Wed, 28 May 2003 09:43:55 -0400

>    if you are an author of one of the drafts covered by

I suspect we are obligated to do something like what Kurt suggests: 
compare and contrast draft-ietf-ldup-lcup with draft-zeilenga-ldup-sync. 
  If we don't, the ADs or IESG will probably make us do so eventually 
anyway.

But I am concerned about process issues surrounding this situation.  Did 
the LDUP WG chairs declare consensus prematurely or inappropriately?  I 
assume the ADs are involved and will help sort this out.  The authors of 
draft-ietf-ldup-lcup did give serious consideration to the ideas 
presented in draft-zeilenga-ldup-sync; some of that discussion took 
place on the mailing list a while ago and some was private mail among 
the authors of the two documents. It is not as if the alternative 
proposal was ignored by the WG or by the LCUP authors.

One additional observation: to remain viable, the IETF needs to accept 
and encourage contributions from many people, not just a few people. 
When a WG deliverable that has been nearly completed is derailed at the 
last moment, the liklihood of the people who volunteered to work on that 
deliverable doing so in the future is greatly reduced. Now, one could 
argue that this is not a technical consideration but a political one. I 
would argue that it is both: the technical quality of the work done in 
the IETF (and the likelihood of widespread implementation) is greatly 
influenced by the number of different implementors who contribute. For 
LDAP related work, we seem to have fewer and fewer contributors each 
year. This is a problem.

> 	c) take another path completely different from those

If you are asking for a vote, I vote for (b). But the larger procedural 
issues (and the ADs) will probably dictate what we must do... and I 
suspect we will end up doing something close to (a).

-Mark Smith
  Netscape

---

From: "Chris Apple" <[email-masked]>
Date: Wed, 28 May 2003 12:19:53 -0400

Thanks for taking the time to post on this topic.

I've included a response to the process concerns below.

DSI Consulting, Inc.

-----Original Message-----
From: Mark C Smith [mailto:[email-masked]] 
Sent: Wednesday, May 28, 2003 9:44 AM
To: [email-masked]
Cc: 'Kurt D. Zeilenga'; [email-masked]; 'John Strassner'
Subject: Re: LDAP Client Update: consideration of alternative proposals

<CHRIS>

From a process perspective, we are obligated to consider Kurt's request.

If consensus is established supporting Kurt's request we become obligated
as a WG to pursue that course of action once that consensus is declared
by John and I.

</CHRIS>

<CHRIS>

With regard to the WG Co-Chairs having declared consensus prematurely
or inappropriately, the jury may be out. I know I have an opinion on
that matter and that's that we did the best we could given the input
received on the mailing list. Currently, this question is not one that
is being formally considered by the ADs.

The ADs were and are involved. That Kurt made the posting to the mailing
list making his request was a result of private discussion held between
Kurt, myself, John Strassner, and both of our ADs. Kurt expressed his
concerns to us privately; we were unable to come to agreement on how to
handle his concerns as a part of the WG Last Call for LCUP; we made a
decision as Co-Chairs that Kurt should take his concerns along with
a specific proposal to the WG Mailing List. John and I have endorsed
the consideration of Kurt's proposal by the WG. That's how we got here.

I agree that the proposal presented in draft-zeilenga-ldup-sync was
given adequate consideration by the LCUP authors and the WG. But again,
the jury may be out on that point. It is still a valid question to ask
though.

Speaking as a Co-Chair, I would have preferred to see all of the technical
discussion between the two author teams related to these two drafts taking
place on the LDUP WG mailing list.

I am hoping that all future discussion related to this topic takes place
on the mailing list.

</CHRIS>

<CHRIS>

I share that concern whole-heartedly.

</CHRIS>

<CHRIS>

The WG will end up doing whatever we establish consensus on. The prior
consensus
is reflected in the current charter. That was reflected in (b). This
discussion
is intended to help us as Co-Chairs determine if there is more support for
one of the options above or another.

Interpreting that requires input on the mailing list. I only hope that
others
are inclined to contribute to the discussion as you've done.

</CHRIS>

-Mark Smith
  Netscape

---

From: [email-masked]
Date: Wed, 28 May 2003 10:26:13 -0700

Mark,
	First, let me say that Chris, John, and Kurt have each
tried to keep Ned and me in the loop on the discussions; I am
also subscribed to the list, so I can and do follow issues raised here.
I have provided a summary of the issues raised to date to the IESG
as a whole, so there is also some awareness of the issues
among those not specifically concerned with the APPs area.
	While all of us (Chairs, ADs, IESG) are concerned both to ensure
an open process and high quality output, we're not here to dictate
the results.  At this point, a working group member has suggested
that the working group reconsider an alternative proposal, and
the chairs have issued a call to the working group to comment on
whether that consideration is needed and should happen.  Two
questions lie at the heart of that call:  has the working group considered
both proposals and come to rough consensus?  if so, should the
working group reconsider its previous decision?
	Previous consideration given to this proposal obviously factors into
the response to that first question.  Assessments of the relative quality
and applicability of the two proposals factors into the second.  So does
the stage of the working group process; as we move forward
through various decisions (adopting drafts as working group
items, setting milestones, and so on), the working group needs
to be able to focus on the next step, rather than revisiting questions
which have been decided.  Our process does allow for reviewing
those questions at any stage (after all, Draft Standards sometimes
recycle at Proposed for exactly this reason), but the reasons to
change a decided issue shift to ones in which fundamental
questions of technical suitability, security, interoperability, or scalability
are at stake.  To put it another way, we are always sensitive
to "show-stoppers" which mean that deployment on the Internet
will be bad for the user or the Internet itself, but that does not
mean all questions must constantly be open for reconsideration.  The
chairs have asked the working group participants in this case to express their
views of whether or not this is needed in this case, and an explicit 
call for consensus
on this point seems to me a good way of resolving the issues.
	Let me say thanks for expressing your concerns and for
giving a response to Chris's call for opinions.  I encourage others
who have opinions to put their fingers to keyboards as well.
				regards,
					Ted Hardie

>...snip...
>compare and contrast draft-ietf-ldup-lcup with 
>draft-zeilenga-ldup-sync.  If we don't, the ADs or IESG will 
>probably make us do so eventually anyway.
>
>But I am concerned about process issues surrounding this situation. 
>Did the LDUP WG chairs declare consensus prematurely or 
>inappropriately?  I assume the ADs are involved and will help sort 
>this out.  The authors of draft-ietf-ldup-lcup did give serious 
>consideration to the ideas presented in draft-zeilenga-ldup-sync; 
>some of that discussion took place on the mailing list a while ago 
>and some was private mail among the authors of the two documents. It 
>is not as if the alternative proposal was ignored by the WG or by 
>the LCUP authors.
>
>One additional observation: to remain viable, the IETF needs to 
>accept and encourage contributions from many people, not just a few 
>people. When a WG deliverable that has been nearly completed is 
>derailed at the last moment, the liklihood of the people who 
>volunteered to work on that deliverable doing so in the future is 
>greatly reduced. Now, one could argue that this is not a technical 
>consideration but a political one. I would argue that it is both: 
>the technical quality of the work done in the IETF (and the 
>likelihood of widespread implementation) is greatly influenced by 
>the number of different implementors who contribute. For LDAP 
>related work, we seem to have fewer and fewer contributors each 
>year. This is a problem.
>
>...snip...
>If you are asking for a vote, I vote for (b). But the larger 
>procedural issues (and the ADs) will probably dictate what we must 
>do... and I suspect we will end up doing something close to (a).
>
>-Mark Smith
>  Netscape

---

From: "Kurt D. Zeilenga" <[email-masked]>
Date: Wed, 28 May 2003 21:35:16 -0700

>Did I miss any key points in your request?

I believe you have captured the key points of my request.

>Do any of them need clarification?

I believe your summary of my request does not need clarification.