LDAP replication requirements [virtual attributes]

[Paul Leach <paulle@xxxxxxxxxxxxx>]

Let me be so bold as to assume that we agree that customers want what I
called "perfect copy" replication. (After some reflection I think I'll
change the name, though -- "perfection" implies too much and be misleading
-- how about I call it "total replication".)

To do total replication, we would need a bunch of things from the
replication protocol. I'm going to put each item in a separate message, to
make commenting easier.

Support for "virtual attributes"

Example: we have user objects in the directory, and we have group objects.
User objects have a "member-of" property. That property is _not_ stored --
for any user object, it is computed dynamically by searching all the group
objects for ones that contain that user object. Thus, updating a group
object will cause a side effect of changing the values on some user object.

There are lots of other instances if the utility of this kind of bahavior:
the "reports-to" and "manager-of" properties of managers and the employess
that report to them, for example.

The knowledge of the relationship between these properties is not captured
or capturable  with the current schema mechanism. It has to be understood
"a-priori" by each replica. So, the representation of schema would need to
be enhanced to support replication of virtual attributes.

Paul