This section describe how schema replication is implemented. and is aimed at users who require an in-depth understanding of the schema replication architecture.
Schema describe the entries that can be stored in a directory server. Schema management is a core feature of the directory service. Replication is also a central feature of the directory service and is essential to a scalable, highly available service.
Any changes made to the schema of an individual directory server must therefore be replicated on all the directory servers that contribute to the same service.
Schema replication occurs when the schema is modified in any of the following ways:
By modifying the cn=schema suffix when the server is online
By using a dedicated task to perform dynamic schema updates by means of a file when the server is online
By modifying the underlying back-end files directly when the server is offline
Generally, schema modifications occur only when deploying new applications or new types of data. The rate of change for schema is therefore low. For this reason, the schema replication implementation favors simplicity over scalability.
Schema replication is enabled by default. In certain specific cases, it might be necessary to have different schema on different directory servers, even when the servers share all or part of their data. In such cases you can disable schema replication, or specify a restricted list of servers that participate in schema replication. For more information, see Configuring Schema Replication in Sun OpenDS Standard Edition 2.2 Administration Guide.