Whenever an enterprise bundle archive (EBA) asset is updated, you can (optionally) update the associated composition unit. You might also update a composition unit to add or remove a composite bundle extension. If any updates need configuration changes, you can also modify the configuration information for the composition unit.
An OSGi composition unit consists of an EBA asset, (optionally) one or more composite bundle extensions, and configuration information for running the asset and composite bundle extensions in a business-level application. If a new OSGi application deployment is available, you can update the OSGi composition unit so that the business-level application uses the newer configuration.
If any updates need configuration changes, you can also modify the configuration information for the composition unit. The configuration information can include HTTP session management, context roots, virtual hosts, security roles, run-as roles, and web application or Blueprint resource reference bindings for your OSGi application.