A transaction begins and commits on a cluster boundary as well. If
something bad happens in the middle of slapadding, the database
will remain intact up to the previous cluster commit. I don't see
this as a limitation as long as the administrator is given the
information on the point his/her slapadd progressed to and as long
as the cluster size is not too large.
I see. I missed the point that this was for slapadd. I thought you
were descibing a mechanism that would be used for regular
LDAP operation processing (ADD, MOD...). I don't think you
need transactions (nor locking) in slapadd.