Distributed Name Service (DNS) Management Operations Manual

DNS Type Names
Introduction to DNS Names
31258 Tandem Computers Incorporated 2–3
Subsystem-Object
Names
An object is any entity controlled by a subsystem, often referred to as a subsystem
object. Most objects are integrated parts of computer systems and networks such as
terminals, lines, printers, and workstations. Objects are also pieces of information
such as personal names, addresses, and phone numbers.
The subsystem-object name is an identifier by which user commands, application
programs, and system software can recognize and refer to the object.
Objects in a system managed by one subsystem are called simple objects; object
managed by multiple subsystems are called composite objects. An example of a
simple object is a file or printer managed by the Guardian 90 operating system. An
example of a composite object is an automated teller machine (ATM) controlled
jointly by the Pathway, SNAX/XF, and SNAX/HLS subsystems.
A subsystem object has a name by which it is known to the subsystem that manages it.
The DNSCOM naming convention for objects with managers is the following:
subsystem-object name UNDER manager name
Pathway, on the other hand, identifies its objects using alphanumeric names of up to
15 characters in length.
DNS Type Names DNS defines subsystem-object types. The purpose of DNS type names is to
distinguish different types of objects (or aliases). They provide a name to like entities,
distinguishing them from different kinds of entities. For example, types distinguish
logical units (LUs), servers, and lines, which are all objects to DNS.
Three DNS types categorize DNS names:
Subsystem-object types categorize subsystem objects. They classify simple objects.
DNS creates subsystem-object type definitions for Tandem subsystems at DNS
initialization.
Composite-object types categorize composite objects (objects known to different
subsystems). They specify the subsystem-object types that must be included in
every instance of a composite-object type. Each subsystem-object type specified in
the definition of the composite type is called a composite type component.
Alias types categorize aliases. An alias is a mnemonic name you create for a long
or complex system name. Some applications are required to distinguish between
multiple aliases for the same object, while others are not. An alias type name is
associated with an alias to distinguish that alias from other aliases that refer to the
same object.
Types can be thought of as templates. First you establish the definition of a type with
its attributes defined, then you associate instances (objects or aliases) to the type that
fit the type (template). The basic premise is that every instance of a particular type
conforms to the definition of its associated type.