faked transactions

[Nahuel Greco <ngreco@axonsis.com.ar>]

Hi, i'm trying to setup an OpenLDAP configuration that mimicks transactional
behavior.
 
I have the following scenario: one LDAP client ("administrator") modifying
an LDAP directory, and multiple LDAP clients ("users") reading from it. The
problem is how to configure OpenLDAP to make the administrator updates
atomic, that is, the administrator (remember, he is only one) can make
any type and quantity of changes to the LDAP directory, but the users
must only see the LDAP directory as it was before the administrator
changes, or as it become after them, but _never_ in a middle state. 

I have been crawling the web and found a draft to add transactions
to the LDAP protocol, but OpenLDAP doesn't appears to implement it 
(it was a possible solution because I can make any changes to the
administrator LDAP programs). So, I'm thinking to fake them, one
possible configuration is:

   administrator ---> LDAP Master server
                           |
                           | "atomic synchronization" 
                           |
                      LDAP Slave server  <---- clients

So, the problem is reduced on how to do that "atomic synchronization",
I haven't found an 'standard' way in OpenLDAP to do that (correct me
if i'm wrong), only a ietf draft (requeriment 6.13 in
draft-weiser-replica-req-01.txt) that isn't implemented (isn't it?).

There is a way to stop the LDAP Slave server resuming the client's
searches but without closing the connections to them, and then
make it retrieve the update from the Master and resume their operations
restarting in a transparent way to the clients?

Note, because the volume of my directory, and the fact that the
master and slave server will run in the same physical machine but
in different ports, is also possible to make the "synchronization"
copying the database files from the master to the slave, but the
problem of stoping the slave without breaking the connections to
the clients persists.

Also, I see in latest OpenLDAP server that transaction support is
in the to-do list. What is the difficult level of implementing them
(I might help but i'm not familiarized with the OpenLDAP codebase). 

Well, any ideas? :) 

Saludos,

Nahuel Greco.