Distributed Name Service (DNS) Management Operations Manual

DNS Object Names
Introduction to DNS Names
2–4 31258 Tandem Computers Incorporated
When creating DNS type and name definitions, first you create a type definition, then
you create an object or alias definition and include an existing type name in the
definition of the object or alias.
By linking the object or alias with its respective type, you assign the object or alias to a
category that classifies it. In the example below, the subsystem-object name TERM26
is added to the DNS database. The subsystem-object type called TERM IN PATHWAY
is included in the ADD command. Thereby, the SSOBJECT TERM26 is of the type
TERM IN PATHWAY.
ADD SSOBJECT TERM26, MANAGER $PM2, TYPE TERM IN PATHWAY
DNS Object Names There are four DNS object names that you can use to group and refer to objects. The
four are: alias, composite, domain, and group names.
Aliases An alias is a mnemonic name you assign to a subsystem-object name or manager
name. Aliases allow you to refer to objects by convenient names instead of system-
defined names. An example of an alias for a terminal named $LINE1.#TERM17
UNDER $ZST is TERM17. Aliases are either typed or untyped. If an alias is associated
to an alias type, it is a typed alias; if it is are not associated to an alias type, it is an
untyped alias. “Defining Alias Type Names”in Section 4 provides more information
about the characteristics of typed alias names.
Knowing an alias, you can use DNS plus a TACL custom command or a management
application to obtain the corresponding object names with the INFO ALIAS command.
Equally helpful, an application that monitors events can use DNS to translate object
names into aliases familiar to you. This name resolution feature is discussed more in
Section 4 under “Defining Alias Names.”
Composites A composite object is an object that is managed by multiple subsystems, as opposed to
a simple object that is managed by only one subsystem. The entities that make up the
composite are called components. Names assigned to composite objects are composite
names. All composite objects are associate to a composite type, defined earlier in this
section.
In a typical use of composites with commands, you give a command (like START),
specifying the name of a composite object (like an ATM). An application uses DNS to
obtain the names that make up the composite, then gives the command to the
appropriate subsystems. Figure 2-1 displays an ATM controlled by a Pathway
terminal, a SNAX/XF logical unit (LU), and a SNAX/HLS session. The ATM in this
example has an alias of ATM-44, which is also its composite name.