RE: WG Charter Proposal v2

At 09:58 PM 4/1/2003, Chris Apple wrote:

>-----Original Message-----
>From: [email protected] [mailto:[email protected]] On
>Behalf Of Kurt D. Zeilenga
>Sent: Tuesday, April 01, 2003 9:25 PM
>To: Mark C Smith
>Cc: [email protected]; [email protected]
>Subject: Re: WG Charter Proposal v2
>
>
>
>At 11:32 AM 4/1/2003, Mark C Smith wrote:
>>Chris Apple wrote:
>>>Well, for starters:
>>>  The following activities are beyond the scope of this WG:
>>>        Revising the LDAP "core" technical specification [RFC3377
>>>        and its normative references] (including its information
>>>       and service models).
>>>
>>>CWA> This is an old discussion based on a perusal of the mailing
>>>     list archive. However, since views may be different now than
>>>     in the past. I think its worth waiting for others to weigh
>>>     in on the issue. If a substantial portion of other WG members
>>>     state their agreement on the mailing list that the suggested
>>>     text be included, John and I can consider whether consensus
>>>     exists on adding it.
>>
>>The working group should proceed with caution. If we adopt a statement such
>as suggested above, an argument could be made that any form of multimaster
>replication requires an extension of the LDAP models... which means such a
>charter statement might prevent the WG from progressing some (most?) of the
>LDUP documents.
>
>Yes, the current documents being produced by the WG assume
>this WG is chartered to revise the LDAP "core" technical
>specification (specifically, LDUP changes the LDAP
>service model) and that's obviously problematic.
>
>CWA> Speaking as a Co-Chair, The WG has achieved consensus
>     on pursuing an experimental publication path - the documents
>     (with the exception of LCUP) produced by this WG, if they
>     actually do *require* changes to the LDAP core specifications
>     to be considered implementable, would surely lead to *experimental*
>     updates and not standards track revisions. So from a process
>     point of view this situation, if it actually becomes a
>     reality, is not as problematic as implied above. 

I think an experimental LDUP would be even more problematic
as it update the service model in a way which would break
non-LDUP-aware clients which excepted standard-track behavior
from the LDUP-aware LDAP servers they peer with.

>However, if the WG intents to continue under that assumption
>that it can revise as necessary the LDAP "core" technical
>specification, then it should say so in its charter.
>
>Or say nothing about this in the charter.  That I don't recommend.
>
>Kurt
>
>CWA> The WG has always intended to handle LDUP specification with
>     LDAPv3 extensibility mechanisms.

The issue is not what mechanisms is used, but whether or
not LDUP specifications revise the LDAP information and service
models in a manner which breaks non-LDUP-aware LDAP implementations.

>Initiating any standards
>     track revisions or updates to the core LDAP specifications
>     would be a last resort. So I don't yet buy into your claim
>     that the existing documents assume that LDUP is chartered
>     to revise the core LDAPv3 specifications. Speaking as a WG
>     member, I'll need some justification of that claim to evaluate
>     it.

I suggest you review the archives of past discussions in this
area.  Here's one URL on the topic (at the head of this thread
you will find an example of a conformant (and common) LDAP use
scenario which LDUP will break.)
  http://www.imc.org/ietf-ldup/mail-archive/msg00672.html

As folks seem not to get the impact MM will have on current
conformant LDAP deployments, I will prepare an I-D on the
subject.  My working title is "Multi-master replication
considered harmful to LDAP/X.500 directory services".

>CWA> Please point out to the WG which LDUP features are impossible
>     or impractical to realize without revising the core LDAPv3
>     specifications,

Multi-master replication without tight data consistency between
the client issuing the modification and the set of master replicas.

>which of those specifications need to
>     be revised,

I suspect most would have to be changed.

>and how those specifications need to be revised
>     for each LDUP feature identified as such.

Basically, they have to ensure that if a modify succeed iff
the update was made to all masters and if a modify failed,
no update to any master is made.  That is, the service
provided to a client in the same regardless of whether there
is one master or many.

Alternatively, eliminate multi-master support.

>You should also
>     provide a proof or some justification of why each of these
>     features is impossible or impractical to realize using an
>     appropriate combination of LDAPv3 extensibility mechanisms.

As I said above, I will write an I-D will details how the
introduction of loss-consistency multi-master replication
will break directory applications.

>     This is the only way for myself or any other WG member to
>     determine if we agree with your belief that this issue is
>     significant enough to address in the charter revision.

Unfornately, I doubt I'll be able to produce an I-D before the
charter revision cutoff.  However, I would hope most LDUP'ers
understand the LDAP service model issue.  It's been discussed
repeatedly on this list.

Kurt