Subject: [ldapext] Support for NSSRs

From: "Jim Sermersheim" <[email-masked]>
Date: Mon, 08 Mar 2004 15:40:16 -0700

All,
 
As we move closer to beginning to define the LDAP distributed directory
model, I propose that we seriously consider dropping support for
non-specific subordinate references (NSSR)s.
 
There are problems in implementing this type of reference, and as far
as I know, there aren't good use cases for it (see Section 9.2 of the
"WEIRD AND WONDERFUL" section at
http://www.isi.salford.ac.uk/staff/dwc/Version.Web/Chapter.9/Chapter9c.htm.
 
One particularly sticky problem is this:
 
Say an NSSR holds five referral URIs. Two point to DSAs that hold
different naming contexts, and three point to DSAs which replicate a
single naming context. There is nothing that sets URIs representing
copies of naming contexts apart from those representing different naming
contexts. Thus, a protocol peer that recieves a searchResultReference
due to this NSSR will erroneously progress the search on two DSAs that
hold the same data.
 
There are other problems when adding subordinate objects to an NSSR.
 
If you know of reasons that NSSRs should be supported, and how these
types of problems can be overcome, please reply.
 
Thanks.
 
Jim