Fractional replication cannot be used in versions of the product prior to Directory Server 5.2. When configuring a fractional replication agreement, both the master and consumer replicas must use at least Directory Server 5.2.
Enabling or modifying a fractional set of attributes requires you to reinitialize the consumer replica. Therefore, you need to determine your fractional replication needs before deployment and define your attribute set before you initialize your replicated suffixes for the first time.
You need to proceed with caution when replicating a small set of attributes, given the dependency of complex features such as ACIs, roles, and CoS on certain attributes. In addition, not replicating other attributes that are mentioned in specifiers or filters of the ACI, roles, or CoS mechanisms might compromise the security of the data. Not replicating might also result in different sets of attributes being returned in searches. Managing a list of attributes to exclude is safer, and less prone to human error, than managing a list of attributes to include.
You need to turn off schema checking in the consumer server if the attribute set that you replicate does not allow all replicated entries to follow the schema. Replication of non-conforming entries does not cause errors because the replication mechanism bypasses schema checking on the consumer. However, the consumer will contain non-conforming entries and should have schema checking turned off to expose a coherent state to its clients.
Fractional replication is configured in the replication agreement of master replicas with hubs and dedicated consumers. Configuration of fractional replication between two master replicas in a multimaster replication environment is not supported. Also, if several masters have replication agreements with the same replica, all these agreements must replicate the same set of attributes.