Schema Replication - Netscape DIRECTORY SERVER 6.01 - DEPLOYMENT Deployment Manual

Schema Replication

In all replication scenarios, before pushing data to consumer servers, the supplier
server checks whether its own version of the schema is in sync with the version of
the schema held on consumer servers.
If the schema entries on both supplier and consumers are the same, the replication
operation proceeds.
If the version of the schema on the supplier server is more recent than the version
stored on the consumer, the supplier server replicates its schema to the consumer
before proceeding with the data replication.
If the version of the schema on the supplier server is older than the version stored
on the consumer, you will probably witness a lot of errors during replication
because the schema on the consumer cannot support the new data.
A consumer might contain replicated data from two suppliers, each with different
schema. Whichever supplier was updated last will "win" and its schema will be
propagated to the consumer.
You must never update the schema on a consumer server because
NOTE
the supplier server is unable to resolve the conflicts that will occur
and replication will fail.
Schema should be maintained on a master supplier server in a
replicated topology. If using the standard 99user.ldif file, these
changes will be replicated to all consumers. When using custom
schema files, ensure that these files are copied to all servers after
making changes on the master supplier. After copying files, the
server must be restarted. Refer to "Creating Custom Schema Files,"
on page 51 for more information.
In Directory Server 6.0, the same server can hold read-write replicas for which it
acts as a supplier, and read-only replicas for which it acts as a consumer. Therefore,
you should always identify the server that will act as a supplier for the schema and
set up replication agreements between this master and all other servers in your
replication environment which should act as consumers for the schema
information..
Special replication agreements are not required to replicate the
NOTE
schema. If replication has been configured between a supplier and a
consumer, schema replication will happen by default.
Using Replication with other Directory Features
Chapter 6 Designing the Replication Process 117