Subject: Replica Management - subtreespecification attribute

From: [email-masked] (Richard V Huber)
Date: Wed, 23 Jan 2002 20:27:03 -0500

We noted in a previous email that, to allow overlapping areas of
replication, we feel that an area of replication is defined by a
replicaSubentry.  The replicaSubentry defines the boundary of the area
via the subtreespecification attribute.

This attribute is inherited from the subentry objectclass defined in
draft-zeilenga-ldap-subentry-00.txt.

Because a subtreespecification may need to be shared across a number of
subentries (e.g. all the replicaSubentries that refer to a common area
of replication), we would like to have a single subtreespecification
that can be referenced from multiple subentries.  Accordingly, we
would like to change the subentry objectclass to use
subtreeSpecificationDN and allow the subtree specification to be stored
as a separate entry which can be referenced as needed.

This may be useful in other cases where a single subtreespecification
needs to be used consistently in several places.

Rick Huber
John McMeeking
Ryan Moats

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From: "Kurt D. Zeilenga" <[email-masked]>
Date: Mon, 28 Jan 2002 13:29:31 -0800

>draft-zeilenga-ldap-subentry-00.txt.

The subentry object class is defined in X.501.  The
draft-zeilenga-ldap-subentry-xx.txt details how X.500
can be accessed using LDAP.  While the syntaxes used
in LDAP differ from those used in DAP, the semantics
are basically the same.

It is the authors' intent to only to define how to
access the this portion of the X.500 administrative
model using LDAP.  Changes to the actual administrative
model are, in our view, beyond the scope of this I-D.
Discussion regarding such changes and/or extensions of
the model should be directed to the appropriate ITU SG
as the ITU has change control over X.501.

I also note that X.500 administrative model allows for
role specific semantics to be associated with certain
aspects of the model.  It might be possible, though not
necessarily appropriate, to associate the desired
semantics with the replication subentry object class.

Kurt

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From: "Steven Legg" <[email-masked]>
Date: Tue, 29 Jan 2002 15:45:38 +1100

Rick,

> via the subtreespecification attribute.

Note that a subtree specification identifies a collection of entries,
but not a subset of the attributes within them. That is, it specifies the
sparseness of a partial replica. Something else in addition to the subtree
specification is required to specify the fractionalness of a partial
replica,
i.e. the attributeExclusionFilter and attributeInclusionFilter attributes.

Regarding terminology, you appear to be using "area of replication" to mean
some part, possibly but not necessarily all, of the information in a
replication
context. Thus a single replication context can have more than one area
of replication within its scope. This is what I assume it means, however
areas of replication (a.k.a replication areas) are not defined in the
architecture and model drafts and tend to be used as synonyms for
"replication context".

> as a separate entry which can be referenced as needed.

This separate (sub?)entry would contain the attributeExclusionFilter and
attributeInclusionFilter attributes as well.

An alternative to a subtreeSpecificationDN attribute would be to place
the replica subentries subordinate to the (sub)entry describing their
area of replication.

Either way, I would support making such a change to the information model.

Regards,
Steven