naming service
A name service is basically responsible for assigning a logical name to a corresponding address - also known as a reference. Name services are used to store attributes of specific objects that are returned as a result of a request. An elementary attribute is the reference. An important aspect in the design of a name service is the definition and structure of a namespace.
A namespace can be organized hierarchically or flatly and also defines the syntactic rules for a name service. Other terms related to name services are their resolution model and navigation variants. Replication as well as caching contribute to a high availability of name services. Naming services are to be distinguished from directory services. Examples of naming services are Java Naming and Directory Interface( JNDI) or Interoperable Naming Service( INS).
The naming service determines the names of devices
Naming services are used to name and identify objects of various types such as computers, services, ports, networks, objects in programming, processes or users. A specific name management takes care of the administration of names, the specification of a structure and the mapping of names to the objects they represent. A namespace comprises the set of all valid names that a specific name service can recognize. In this context, a namespace is always syntactically defined and can be either flat (i.e., without structure) or hierarchical with structures such as path names oriented to the operating system. The assignment between an object and a name is called binding. The transformation of a name into its associated address is called resolution.
Standard operations of name services
A name service always provides the following standard operations:
Bind a name (bind), Resolve a registered name (resolve), Clear a name (clear), Search based on names (White Page Service), and Search based on attributes (Yellow Page Service).
The name service thus allows resources to be accessed by names instead of physical addresses, which must be known throughout the system for this purpose. A directory service extends this principle. First of all, a directory in this context is defined as a listing that groups together in a certain order names and attributes of, for example, users, computers, services, or remote objects. And a directory service searches this collection for entries of names corresponding to certain entries. Directory services are also called attributed name services, which resolve name references according to, for example, computer names, addresses, and other information.
To differentiate: A name service corresponds to the telephone book - the name must be known for access. A directory service is similar to the Yellow Pages - a name is not known, but a service can be represented by meta information.
Other examples of name services are: Internet Domain Name System( DNS), Java Name and Directory Interface (JNDI), Interoperable Naming Service (INS, CORBA) or Java Remote Method Invocation( RMI). Other examples of directory services include: Global Naming Standard( GNS), X.500 Directory Service or Lightweight Directory Access Protocol( LDAP).