Distributed Name Service (DNS) Management Operations Manual

How to Define DNS Names
Building and Modifying the DNS Database
4–12 31258 Tandem Computers Incorporated
EXTERNAL Attribute for SSTYPE Definitions
The EXTERNAL attribute used for an SSTYPE definition can play a useful part in the
definitions of names associated with an SSTYPE. If the EXTERNAL attribute is set to
ON in an SSTYPE definition, subsystem-object names of this type are automatically
added as aliases.
DOMAIN Attribute for SSTYPE Definitions
If a domain name is specified in an SSTYPE definition, instances of the subsystem-
object type, that is, SSOBJECTs, automatically inherit the DOMAIN attribute of this
SSTYPE by default.
A default attribute can always be overridden when the attribute is specifically defined
in a definition. See the explanations below for the specific effects of specifying a
domain name for a SSOBJECT definition.
A SSOBJECT has the same domain as the one specified in its associated SSTYPE
definition, if the domain attribute is not explicitly specified in the SSOBJECT
definition.
Moreover, an untyped ALIAS created for this SSOBJECT has the same default domain
as the SSOBJECT (as long as the ALIAS definition does not specifically specify a
domain).
Specific Characteristics for SSTYPE Names
Names selected for subsystem-object types must have the following characteristics:
Start with a letter and be composed of alphanumeric characters. Embedded dash
characters (-) can be used as separators
Be no more than eight characters long
Be unique in each subsystem in which they are defined
Defining Manager Names The identification of manager processes (SSMANAGER) is important to DNS for two
significant reasons:
1. Subsystem-object names might not be unique. For example, a test Pathway system
(with Pathmon name $TPM) may exist on the same node as a production Pathway
system (with Pathmon name $PPM) with both systems having a server class called
NEW-EMPLOYEE.
Although these two objects have the same subsystem-object name, they are unique
objects because they are controlled by different subsystem managers (Pathmons).
The “Uniqueness of Names: Parts of a DNS Name“ subsection earlier in this
section discusses unique names in more detail.
2. A management application might not be able to determine what the manager
process is if given only the subsystem-object name and type. For example,
knowing that TERM06 is a Pathway TERM is not sufficient; the application also
needs to know which Pathmon controls TERM06. This is why SSMANAGER
names are associated to subsystem-object names.