Subject: Re: Multiple extended responses per request

From: "Dave Wilbur" <[email-masked]>
Date: Fri, 10 Sep 1999 10:37:07 -0600

Thanks for the feedback from Bruce and Kurt.

The suggestion that each response be prompted by a 
request could also be used for Persistent Search (as well 
as a standard Search, for that matter).  The fact that Search 
saw a need (to reduce overhead, other?) to allow for multiple 
responses to a request, in the form of entries and a result 
leads me to believe that an extension should be able to 
accomplish similar functionality.

The fact that Kurt suggested that we CAN do multiple 
responses per exteded request leads me to believe that 
there are others who think this should be allowed.  Currently 
the RFC implies that you only get one Extended Response 
per request and the client SDKs are implemented so that you 
can only retrieve one response per request.  So if we are to 
allow multiple resonses per request, then the RFC should state 
this and the SDKs should support it.

Dave

>>> "Kurt D. Zeilenga" <[email-masked]> 9/9/99 10:13:51 AM >>>
At 08:48 AM 9/9/99 -0700, Bruce Greenblatt wrote:
>Hi Dave!
>
>You'll want to do something similar to the multi-stage bind.

Or something similiar to what search does:

CLIENT                                               SERVER
              Extended Request
        ------------------------------------------>

              Extended Response (not done)
        <------------------------------------------
              Extended Response (not done)
        <------------------------------------------
              Extended Response (not done)
        <------------------------------------------
              Extended Response (not done)
        <------------------------------------------
              Extended Response (not done)
        <------------------------------------------
              Extended Response (not done)
        <------------------------------------------
              Extended Response (done)
        <------------------------------------------

At 03:50 PM 9/8/99 -0600, Dave Wilbur wrote:
>While developing an LDAP v3 extension, a developer here wanted to be able
to send multiple responses against one request.  This was relatively easy
to support in our server code, but the published client APIs don't support
more than one response per message id.  While RFC 2251 for LDAPResult is
quite clear in stating "to indicate the *final* status of a protocol
operation request", the ExtendedResponse is not quite so definitive: "The
server will respond to this with an LDAPMessge containing the
ExtendedResponse."
>
>Given the precedent of an interim response in the Search verb as well as
Persistent and Triggered search, it seems to make sense that an Extension
might want to do this as well.  We were going to use different OIDs to
indicate if a response was interim or final until we ran into the client
issue.
>
>Is this feasible? reasonable?
>
>Looking for feedback.
>
>Dave

---

From: [email-masked] (Mark C Smith)
Date: Fri, 10 Sep 1999 13:32:07 -0400

I don't have a strong opinion about whether multiple ExtendedResponses
should be allowed in response to one ExtendedRequest, but my reading of
2251 tells me that the authors didn't intend to support it.  In the C
API, one could call the asynchronous ldap_extended_operation() function
once and then repeatedly call ldap_result() followed by
ldap_parse_extended_result() to receive and process a stream of
ExtendedResponse messages.  But I agree we should clarify whether the
protocol supports this and improve the APIs as necessary to support it
if so.

-- 
Mark Smith
iPlanet Directory Architect / Sun-Netscape Alliance
My words are my own, not my employer's.   Got LDAP?

---

From: Mark Wahl <[email-masked]>
Date: Fri, 10 Sep 1999 12:49:44 -0500

Only the LDAP Search Request allows multiple distinct LDAPMessages to be 
returned.  There can only be one ExtendedResponse to an ExtendedRequest.

Mark Wahl, Directory Product Architect
Innosoft International, Inc.