Re: draft-ietf-ldapbis-protocol - controls

["Kurt D. Zeilenga" <Kurt@OpenLDAP.org>]

At 10:14 PM 3/31/2005, Mark Ennis wrote:
>Kurt D. Zeilenga wrote:
>>At 08:49 PM 3/31/2005, Jim Sermersheim wrote:
>>
>>>I believe the broad interpretation of "appropriate" leads to far
>>>more interoperability problems than the narrow view.
>>>I'm glad to see that you don't believe a control can be partially
>>>applied.
>>
>>This, I think, needs to be made crystal clear.
>A control which results in modification of multiple objects must not be partially applied, but what about a control that modifies the behaviour of a query?

Meaning that given a request+control where the control is non-critical,
the server is to perform either the operation indicated by the
request OR to perform the operation indicated by request+control.

The server cannot perform a portion of the operation as indicated
by request+control and a portion of the operation as indicated
by request.  For instance, it would be inappropriate for a
server, in response to a search+manageDsaIt request, to only
apply the semantics indicated by the manageDsaIt to a subset
of the results.  The server is obligated to apply those semantics
across all results or no results.

>A control requesting extra information from each entry in a search result, for example a control to reproduce the behaviour of the modifyRightsRequest in a DAP read operation, may be partially applied, without having any serious implications.

Different kind of "apply".  If the prescribed semantics of the
operation indicated by request+control allow for some of these
modifications to be applied to the DIT and others not, that fine.
But if the prescribed semantics of this operation required that
all or none of these modifications to be applied to the DIT, then
that's what has to be done in performance of that operation.

>To what extent should the allowance to partially apply a control be regulated by the specification controlling the infrastructure, i.e. [protocols], versus the control specification?

The control specification defines what operation to perform
in response to a request+control message.

Where the control is non-critical, the server has a choice of
perform either:
        the operation indicated by the request as extended by the control
or
        the operation indicated by the request.

Performing some other operation is not an option.

>For example, a control specification for a tree delete control should include a discussion of considerations relating to application of the control in a distributed environment or across different contexts, regardless of what [protocols] may say.