Re: LCUP issue: trigger mechanism or not?

Jim Sermersheim wrote:
 >
> The draft states that it "is intended to allow LDAP clients to
> synchronize with the content stored by LDAP servers". but also states
> that it wants to solve the problem of triggered actions (Section 3,
> Bullet 3).

I agree that triggered actions should be within LCUP's scope. The LCUP 
authors have tried to balance the server implementation burden with the 
client implementation burden. In particular, I would really like to 
avoid creating an LCUP protocol that requires a server to store 
client-specific state (that just won't scale when their are thousands or 
hundreds of thousands of clients).


> Most of the rest of the draft is consistent with the notion of
> synchronization, but tends to downplay support for triggered responses.
> Do we want this to be a useful event driver, or is the idea that we just
> preserve the easy stuff of what prior drafts could do?
> 
> Specifically, the left-out items in Sections 5.1, 5.2, and 5.3 deter
> from the effectiveness of the "persist" mode.
> 
> Curent users of Persistent Search rely on the notion of change types.
> Section 5.2 assumes that change types are used for partial replication,
> and thus discounts them as useful for LCUP. I don't think this is
> valid.

Are you saying that LCUP should support clients that only want to store 
  a subset of the entries that are targetted by the LCUP search they 
issue? Even if you do want to support that, I don't see the problem. The 
LCUP model (as defined today) is that it is up to the client to 
determine whether a change is interesting or not. The assumption is that 
clients will store UUIDs for each entry they are interested in, and that 
the client can compare stored data with the new entry data to determine 
what has changed. That does not seem like an excessive burden to me.

A related comment: perhaps section 5 should be moved to an appendix that 
is named "Features Left Out of LCUP." It is not core to LCUP, but is 
useful to provide historical context and rationale for why some things 
are not included in LCUP.

-Mark Smith
  Netscape