Subject: WG Consensus: Abandon Operation

From: "Kurt D. Zeilenga" <[email-masked]>
Date: Thu, 01 Aug 2002 00:44:00 -0700

The message summarizes the WG discussions of Abandon
operations.

There is no evidence that any implementation returns or
expects the return of a response for an abandoned operation.
The fact that no specific result code indicating abandonment
was defined in the LDAP technical specification is a clear
indication that no response was to be returned in the case
of abandonment.

While some are concerned that design of Abandon operation is
flawed (as it doesn't provide a clear indication of
abandonment), redesign of the Abandon operation is beyond
our scope of work.  This work has been undertaken on an
individual basis (see draft-zeilenga-ldap-cancel).

The chairs believe there is consensus that the
Abandon operation and message ID reuse (in regards to the
Abandon operation) sections should be clarified to clearly
indicate:
	* Servers are not required to honor the Abandon
	  request;
	* The Abandon operation has no response;
	* The abandoned operation has no response; and
	* Message ids of the Abandon operation and the
	  abandoned operation cannot be reused unless
	  a subsequent bind operation completes.

The Editor is directed to produce a revision containing
clarifications consistent with this consensus.  The WG
should review the clarifications once offered to ensure
that they do reflect this consensus.

The chairs draw no conclusion as to the applicability of
the Abandon operation to abandon update operations.  The
chairs suggest that those who believe that some statement
should be added to the technical specification regarding
use of the Abandon operation to abandon update operations
should offer a specific proposal for WG review.

-- Kurt & Bob

---

From: David Chadwick <[email-masked]>
Date: Fri, 09 Aug 2002 20:51:45 +0100

Kurt

I support your conclusions so far, but dont think they go far enough for
the following reason

    -  it would be foolish to issue an RFC when it is currently unclear
whether Abandon can or cannot be used on an update operation.

I therefore think that further clarification text is needed in addition
to what you have already proposed, so as to remove any ambiguity over
the use of Abandon on updates. It seems like we have three choices

i) To state explicitly that Abandon cannot be used against update
operations, as per the X.500 protocols. We may need to state what
happens if this is attempted (e.g. protocol error or similar)

ii) To state explicitly that Abandon can be used against update
operations, and to state what the outcomes are in all conceivable cases
(new text will be needed here as X.500 wont give you any help)

iii) To state that this document gives no guidance as to the use of
Abandon with update operations, and it is a local implementation matter
how they are handled.

regards

David

-- 
*****************************************************************

David W. Chadwick, BSc PhD
Professor of Information Systems Security
IS Institute, University of Salford, Salford M5 4WT
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Email: [email-masked]
Home Page:  http://www.salford.ac.uk/its024/chadwick.htm
Research Projects: http://sec.isi.salford.ac.uk
Understanding X.500:  http://www.salford.ac.uk/its024/X500.htm
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---

From: "Kurt D. Zeilenga" <[email-masked]>
Date: Fri, 09 Aug 2002 17:59:44 -0700

I've changed the subject to distinguish them from the
issues we've reached consensus upon (as detailed in
the 'WG Consensus: Abandon Operation' post)...

>Abandon with update operations, and it is a local implementation matter

In my opinion, RFC 2251 is fairly clear that:
 a) the Abandon operation can be used to request the abandonment
    of any outstanding operation,
 b) this Abandon request may not be honored.

but I also believe:
 c) the Abandon operation should only be used to abandon search
    operations (abandoning compare is pointless, abandoning
    other non-update operations, e.g. bind and starttls, is
    problematic, and abandoning update is also problematic).

To address this, I think [protocol] should state that abandon
should not be used where the client needs a clear indication
of whether abandonment occurred or not and, then, discuss
cases where a clear indication is (generally) needed.

That is, don't prohibit implementation of Abandon operation for
non-search, just provide guidance for its use.

Kurt

---

From: David Chadwick <[email-masked]>
Date: Sat, 10 Aug 2002 19:37:20 +0100

> non-search, just provide guidance for its use.

Ok, thats clearly an improvement on the current situation. And you are
then letting the user decide, after providing full details of the
implications

David