Grid Objects and Object Naming
Each entity in a grid—such as each host, instance, installation, and repository—is defined as a named object.
Each object type, representing these types of entities, has its own namespace. You can have a host named xyz
and a repository named xyz
without conflict. In addition, instance namespaces and installation namespaces are per host. You can have an instance named instance1
on host1
and an instance named instance1
on host2
without conflict.
Object-naming hierarchies such as this can be expressed in ttGridAdmin
syntax using fully qualified names, toplevelobject
.
nextlevelobect
. For example, host1.instance1
and host2.instance1
. To specify an instance or installation in ttGridAdmin
syntax, you need only specify hostname
(instead of hostname
.instancename
or hostname
.installname
) if there is only one instance or installation (as applicable) on the host.
Operations on grid entities through ttGridAdmin
, such as creating or removing an instance or installation, are managed through the corresponding objects in the model. The physical entities themselves are not created or removed until the model is applied through the ttGridAdmin modelApply
command. For example, to remove an instance named host1.instance1
, the instanceDelete
command removes the object named host1.instance1
from the model, then the modelApply
command removes the physical instance (the instance home directory and everything under it).
Be aware of these limitations in object naming in the grid model:
-
Names must use only ASCII characters.
-
Allowed characters are alphabetic, numeric, hyphen (
-
), and underscore (_
). -
Database definition names and connectable names are limited to 32 characters (due to ODBC limitations).
-
All other object names are limited to 256 characters.
-
Object names are case-insensitive (so you cannot have an instance
instance
and an instanceInstance
on the same host), but are represented and shown as specified inttGridAdmin
commands. If you specifyMyInstance
in theinstanceCreate
command, that is how it will be shown. -
You cannot name anything
All
orDefault
, which are reserved names.