Re: LDUP "orphan" entries

[Steven Legg <s.legg@xxxxxxxxxxxxxxxxxx>]

I'm not sure whether you are asking for an example of how the situation might
arise where a DSA receives a request via LDUP to remove an entry with
subordinates, or if you are asking what the conflict resolution would be
in such a case.

Let's suppose that some entry E exists in two replicating DSAs.

At DSA 1 a client adds subordinate entries to E. A client at DSA 2 removes
E, which is allowed because DSA 2 hasn't yet seen the requests to add the
subordinate entries. When the two DSAs exchange their changes DSA 1 sees a
request to delete E despite the fact that from its point of view E has
subordinates. DSA 2 sees the other side of the problem. It sees requests to
add subordinates to an entry which has been deleted. In both cases the
subordinate entries become orphaned.

Each replication agreement nominates an entry, which we have called
Lost & Found, as the place to put orphaned entries. In the above example
both DSAs move the orphaned subordinate entries under Lost & Found.

Regards,
Steven Legg
Telstra Research Laboratories

Sukanta Ganguly wrote:
> 
> How is it possible to delete an entry in LDUP when it subordinates exists? Could you eloborate a little more on this, Steven.
> 
> Sukanta Ganguly
> 
> >>> Steven Legg <s.legg@xxxxxxxxxxxxxxxxxx> 12/15/98 06:24PM >>>
> 
> Mike,
> 
> > I dont' see why "orphan entries" should be possible.  An LDAPv3 client can't
> > create them by interacting with a single server.  Didn't you say (or want to
> > say) you want the result of conflict detection and resolution to be equivalent
> > to some possible interaction series with a single server?
> 
> We are not trying to say that the operations from multiple sources must
> correspond to a possible sequence of LDAP operations once combined. All we are
> saying is that the effects of one operation, such as they are, occur either
> entirely before or entirely after every other operation. The effect of an
> operation may not ultimately be exactly what happened at the source DSA.
> The effect may also circumvent a constraint normally applied to an operation
> of that type. For example, it is illegal to delete an entry with subordinates,
> but such a circumstance arises in LDUP so we need to deal with the problem
> of orphaned entries.
> 
> Regards,
> Steven Legg
> Telstra Research Laboratories
> 
>