Re: draft-ietf-ldapext-ldapv3-txn-00.txt More ..

[dboreham@netscape.com (David Boreham)]

Harald Tveit Alvestrand wrote:

> Small comment:
> Might the DSAs use a transaction protocol such as that described in
> draft-lyon-itp-nodes-07.txt to coordinate the locking between them?
>
> The span would go roughly between Client, Server1 and Server2:
>
> Client -> Server1: Start transaction
>        <- OK
> Client -> Server2: Join transaction
> Server2 -> Server1 (TIP): Join
>         <- OK
> Client <- Server2: OK
> Client -> both servers: Stuff
> Client -> Server1: Finished
> Server1 -> Server2: OK to finish?
> Client -> Server2: Finished
> Server2 -> Server1: Yes, I'm OK to finish
> Server1 -> Server2: Let's do it
> Server2 -> Server1: OK, it's done
> Server1 -> Client: OK
> Server2 -> Client: OK
>
> This is fairly standard technology, I believe.
> It's getting the details right that hurts.

I believe this is a form of 2-phase commit,
which the document specifically doesn't address.
If there is interest in extending the scheme to
support 2PC (which roughly involves adding
a "prepare" command, and some scheme
for co-ordinating recovery), it wouldn't be
hard to extend the protocol.
Let's hear from some of the more database-savvy
people on the list perhaps ?