Now that https://fedorahosted.org/389/ticket/48755 is merged, I would
like to discuss the way we handle CSN with relation to this master. As
I'm not an expert on this topic, I want to get the input of everyone
Following this document:
As I understand it, after a full online init, the replica that consumed
the changes does not set it's CSN to match the CSN of the master that
sent the changes.
As a result, after the online init, this causes a number of changes to
be replicated from the sending master to the consumer. These are ignored
by the URP, and we continue.
However, in a number of cases these are *not* ignored, and have caused
us some bugs in replication in the past. We also have some failing
changes that are skipped, which could in certain circumstance lead to
inconsistency in replicas. We have gone to a lot of effort to be able to
skip changes, to handle the case above.
The reason was is that if there was a modrdn performed, and the entry ID
of the entry that was moved was less than the new parent ID, this *had*
to be skipped, so that after the online init the modrdn change was
replayed and applied to the consumer.
Since 48755 which sorts based on the parent ID, this seems to no longer
be an issue. So we don't need to have the master replay it's changelog
out to the consumer, because the consumer is now a literal clone of the
So, is there a reason for us to leave the CSN of the consumer low to
allow this replay to occur? Or can we alter the behaviour of the
consumer to set it's CSN to the CSN of the sending master, so that we
don't need to replay these changes?
Red Hat, Brisbane