Network Working                                  S.E. Hardcastle-Kille
Group                                        University College London
INTERNET-DRAFT                                              April 1992







               Counting the Directory Information Tree
                             (OSI-DS 30)






Status of this Memo

Pilot Directory Services are growing rapidly.  It is useful to know
how much information is available in the directory.  This is important
for management purposes, both to understand the level of growth, and
to provide publicity as to what is there.  Current counting techniques
are both ad hoc and implementation specific.

A more general technique is proposed here.  It is likely that such
estimates will always be on the low side, for example because an
organisation is not prepared to indicate the number of entries is has.
However, it is useful to be able to estimate the size of the Directory
Information Tree.  This specification defines a means for doing this.

This draft document will be submitted to the RFC editor as a protocol
specification.  Distribution of this memo is unlimited.  Please send
comments to the author or to the discussion group
<osi-ds@CS.UCL.AC.UK>.




Internet Draft               Counting the DIT               April 1992



SingleLevelCount ATTRIBUTE
        WITH SYNTAX integerSyntax


SubtreeCount ATTRIBUTE
        WITH SYNTAX integerSyntax


TypedSubtreeCount ATTRIBUTE
        WITH SYNTAX  SET -
                objectClass OBJECT IDENTIFIER,
                count INTEGER "





                  Figure 1:  Attributes for DIT Size


1  Attribute Definitions

Attributes are defined to indicate the size of the DIT Figure 1.
These attributes are associated with every non-leaf node in the DIT.
The attributes have the following semantics.

SingleLevelCount The number of entries at the level below.

SubtreeCount The number of entries in the entire subtree.

TypedSubtreeCount The number of entries, divided by object class.
    The list of object classes provided is up to the node manager.
    Where appropriate, it should contain at least:  Person;
    Organisation; Organisational Unit; Application Entity; Locality;
    DSA; Role.


2  Count Maintenance


There are several means of maintaining the counts.



Hardcastle-Kille                                                Page 1




Internet Draft               Counting the DIT               April 1992


2.1  Manual

The manager inserts the counts manually.  This is appropriate for
small organisations, or in cases where there is no automatic support.


2.2  Manager Script

A simple script can be written for each level to count at the level
below, and to write the appropriate values in a node.  In an
organisation, this could be run for each department, and then again to
total the departments.  This procedure could be run each night to keep
totals up to date.

2.3  Automatic by DSA


These counts could be maintained by DSAs with control over the data at
the correct level.  This would enable counts to be updated very
frequently, and to propagate upwards.
It might be possible one day to have a steadily changing monitor,
indicating the total number of entries in the DIT.


3  Security Considerations

Security considerations are not discussed in this Internet Draft.


4  Author's Address

    Steve Kille
    Department of Computer Science
    University College London
    Gower Street
    WC1E 6BT
    England


    Phone:  +44-71-380-7294

    EMail:  S.Kille@CS.UCL.AC.UK



Hardcastle-Kille                                                Page 2