1. Reference
  2. TimesTen Scaleout Utilities
  3. ttGridAdmin
  4. Grid Objects and Object Naming

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 instance Instance on the same host), but are represented and shown as specified in ttGridAdmin commands. If you specify MyInstance in the instanceCreate command, that is how it will be shown.

  • You cannot name anything All or Default, which are reserved names.