The Cloud Data Management Interface (CDMI) is a standard that is being developed by The Storage Networking Industry Association (SNIA). The SNIA explored the different management interfaces (Control interfaces) that are integrated into cloud offerings and have created a model that can be mapped to various offerings. The emergent model—Cloud Storage Reference Model–is a standardized functional container interface for supporting legacy and new applications. Metadata can be set on containers and the data elements contained therein for effective management of data stores. The containers, accounts, security protocols and monitoring/billing information underlying storage services can be exposed to IT Administrators who are vendors/consumers of cloud services.
Representational State Transfer (REST) design principles have been used in putting together the GUI. Cloud storage vendors can implement the interface by integrating the “adapter” with their existing proprietary interface or implement the interface directly, along with the existing interface. A number of client libraries can also be adapted to this interface.
Data operations on the client interface revolve around container objects and data objects. Each object is identified with a unique identifier that is generated at the time it is created. The data path implementation must support at least one level of containers. New containers may be created with specified names and key/value metadata may or may not be specified. Other Key/value pairs can be used to specify the data requirements at an object level as defined in the CDMI specification. The queue object is a special object that is used to define certain special properties for certain categories of data. Each container may expose a block protocol or a file protocol and is an abstraction for applying data system metadata. The Meta data attaches to the structures and maps the bloc storage location by Logical Block Addresses. This makes it possible for cloud offerings to support domains and allow administrative ownership associations for stored objects.
Different types of metadata are defined in the CDMI standard such as http metadata, data system metadata, and storage system metadata. Http metadata may define content size or content type. Data System metadata abstractly specifies the data requirements of the data services deployed in the cloud storage system. These settings are treated as goals or even as actual measures of achievements of goals specified. User defined metadata is arbitrarily defined. This is attached to objects and the namespace used for the purpose is self administered. Storage system metadata is read only metadata that is automatically generated by the storage system.
CDMI security embraces transport security, user and entity authentication, authorization and access controls, data integrity, data media sanitization, data retention, data protection, data encryption and other security measures. The adoption of CDMI mandates the implementation of transport security and security capability queries. Other security measures can be customized to the needs of the vendor/user.