Defining Directory-Services Terminology

Now that you have seen the very basics of directory services and to avoid any confusion with similar terms used in different contexts, the following definitions apply to the terms used in the directory services lessons of this book:

• Directory service: Process(es), protocol(s), and data store(s) that provide a method for requesting data and receiving that data in a scalable, centralized, and distributable manner. An example of a complete directory service would be Lightweight Directory Access Protocol (LDAP), where the process is slapd, the protocol is LDAP, and the data store is a Berkeley DB database.

• Protocol: A common set of rules to request and receive data. For example, LDAP is a protocol for communicating between requestors and an LDAP directory.

• Process: Executables that handle client requests and retrieve data. Two examples are slapd (for accessing LDAP directories) and netinfod (for accessing NetInfo databases).

• Data store: A specialized read-optimized database, such as a set of flat files.

• Directory: A data store that follows a particular way of organizing data for a directory service. A Berkeley DB database that is structured to be accessed via LDAP is an LDAP directory.

• Directory domain: A logical grouping of data.

• Open Directory: Apple's overall name for the implementation of directory services in Mac OS X and Mac OS X Server.

• DirectoryService: The actual process that handles directory service calls in Mac OS X and Mac OS X Server, and passes those requests to other directory services based on a plug-in architecture.

By defining certain aspects of the directory structure, it's easy to see how these pieces work together to provide the requestor with information from the data store.