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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