[389-users] replication with some attributes excluded leads to schema violation

[Petr Spacek]

Hello 389 users and developers,

I would be very happy if somebody could give me any advice about "the right 
way" to solve this problem:

I have following objectClass in the schema:
objectClasses: ( 2.16.840.1.113730.3.8.6.1 NAME 'idnsZone' DESC 'Zone class' 
SUP idnsRecord STRUCTURAL MUST ( idnsName $ idnsZoneActive $ idnsSOAmName $ 
idnsSOArName $ idnsSOAserial $ idnsSOArefresh $ idnsSOAretry $ idnsSOAexpire $ 
idnsSOAminimum ) MAY ( idnsUpdatePolicy $ idnsAllowQuery $ idnsAllowTransfer $ 
idnsAllowSyncPTR $ idnsForwardPolicy $ idnsForwarders ) )

Please note MUST attribute idnsSOAserial.

I have two 389 servers on RHEL 6.4 with the same schema:
389-ds-base-1.2.11.15-10.el6.x86_64

There is multi master replication agreement between machines vm-115<->vm-042.

Attribute idnsSOAserial is excluded from incremental replication (export from 
vm-042):
cn=meTovm-115,cn=replica,cn=dc\3Dexample,cn=mapping tree,cn=config

idnsSOAserial: (objectclass=*) $ EXCLUDE memberof idnssoaserial entryusn 
krblastsuccessfulauth krblastfailedauth krbloginfailedcount

nsDS5ReplicatedAttributeListTotal: (objectclass=*) $ EXCLUDE entryusn 
krblastsuccessfulauth krblastfailedauth krbloginfailedcount


Now I create a new object with objectClass idnsZone on vm-042. The new object 
is replicated to vm-115, but the attribute idnsSOAserial is missing - and this 
fact violates the schema.


Is it expected behaviour?

What I misunderstood?

Which approach you recommend to application developers for dealing with such 
situation?

I don't like the approach where application have to go to *all* DS to 
initialize the excluded attribute, because:
What the application should do if it's unable to connect to one of DSs?

What if rollback is impossible? (E.g. attribute was initialized on replica1 
and replica2 but the link from application to the world failed before replica3 
was initialized.)

Would it be possible to configure DS to replicate the attribute when object is 
created but not replicate further changes? It would defer all problems above 
to DS replication mechanism and simplify applications :-)

Thank you for your time!


I'm not subscribed to this list, please include me in Cc explicitly.

-- 
Petr Spacek
Software engineer
Red Hat Czech, BRQ