Express (Distributed operating systems), v8.0 > Secure applications and their environment > Authenticate users > Select a registry or repository > Manage realms in a federated repository > Virtual member manager > Develop with virtual member manager > Extend virtual member manager functionality in the application
Schema loading process and schema extension in a multiple security domain environment
In a multiple security domain environment, each domain has its own copy of the virtual member manager schema.
Virtual member manager loads all the schema model packages in a single class loader EMF registry. All schemas are stored and extended in the WAS Extension Class Loader domain-specific EMF registry, which is visible to all applications within that domain. In scenarios where virtual member manager is initialized by a user application (or local mode) instead of WAS, the schema is stored in the EMF registry that is specific to the application Class Loader.
In a multiple security domain environment, you can set the useGlobalSchema property to use the global schema instead of the domain-specific schema. Global schema refers to the schema of the admin domain. If you are using an out-of-the-box schema without any schema extensions, you can use the global schema to avoid duplicate schemas for each of the domains. This saves memory resulting in better performance.
Avoid trouble: Application domains that are set to use global schema share the same schema of the admin domain. Hence, if you extend the schema for an application in one domain, consider how that might affect applications of other domains as they are also bound by the same schema. For example, adding a mandatory property for one application might cause other applications to fail.
For more information about setting the useGlobalSchema property using the wsadmin command, setIdMgrUseGlobalSchemaForModel, see the topic, IdMgrConfig command group for the AdminTask object in the WAS information center.
Parent topic: Extend virtual member manager functionality in the application