Layering terms and concepts

Layer object

A special type of object which is not managed by TOM.

When a layer object is defined, TOM does not start, stop, or manage the layer object. Instead, the layer object’s definition serves as a template for generating similar objects on another system (or on all the systems) in a sysplex.

Layer objects are created on the object ADD or EDIT dialog by specifying a pattern name for a layer object in the Pattern field in addition to a name in the Name field. The naming convention of the pattern name uses a combination of variables and user-specified literal characters. TOM uses the pattern name to create the names of the objects generated from the layer object.

The layering application generates and propagates the layer object definitions, dependencies, and schedule to other systems or sysplexes. For information about the naming convention for layer objects, see Layer-patterns-for-objects-and-sets.

Layer set

A special type of set that contains only layer objects and layer sets.

TOM does not start, stop, or manage a layer set. Instead, the layer set’s definition serves as a template for generating similar sets of objects on another system (or on all the systems) in a sysplex. For information about the naming conventions for layer sets, see Layer-patterns-for-objects-and-sets.

Layer sets are created on the TSET view with the ADD primary command. On the New Name dialog, specify a name for the set and layer pattern set name in the Layer Pattern field in addition to a set name. The naming convention of the layer pattern name uses a combination of variables and user-specified literal characters. TOM uses the layer pattern name to create the names of the sets generated from the layer set.

System layers

A grouping of layer objects and layer sets.

System layers allow you to logically group similar layer objects and layer sets together. For example, during your layer object planning phase, you can group all the layer objects that represent CICS objects into one system layer and all the WebSphere objects into a separate system layer. This grouping will make it easier to maintain similar layer objects and sets over time.

System layers are also helpful if you want to group together a collection of the basic objects that are common to every system across multiple sysplexes. You can use this system layer to quickly and easily populate systems on one or more sysplexes.

Sysplex layers

A grouping of one or more system layers.

By having well organized system layers, you have more options when managing the sysplex layer.  For example, one sysplex layer may contain the BasicObjects system layer, the CICS system layer, and the WebSpher system layer.  Another sysplex layer may contain the BasicObjects system layer, the DataBase system layer and the DataBaseAppls system layer.

With sysplex layers, you can easily generate and update many objects and sets for a sysplex in a single action.

System pool

A grouping of one or more systems from one or more sysplexes.

System pools allow you to define moveable layer objects more easily.

System pools resolve into system names specific to the sysplex during the attachment and propagation processes.

Layer ID

An identification number assigned to each system within a sysplex.

The layer ID can be used in a Valid System List entry of a layer object which generates an object that can run on more than one system in a sysplex.  The format of the system name for such an entry is &SYSnnnn where nnnn is a number from 1 to 9999.

Assigning layer IDs to all systems in the sysplexes simplifies the process of creating layer object definitions. The layer ID represents a virtual system name that is resolved during the attachment and propagation processes.

ATTACH

A command that generates objects and sets from the layer objects and layer sets.

You can ATTACH a system layer to a system which will generate objects and sets for that system.

You can ATTACH a sysplex layer to a sysplex which will generate objects and sets for the systems in the sysplex.

DETACH

A command that deletes the objects and sets that were generated by the ATTACH command.

Propagation

Any updates made in the layer definitions are also applied to the objects generated from that layer.

For example, if a layer object is updated, any objects generated with that layer definition will be updated with the same change.  Another example, if a layer system is updated to remove a layer object, all generated objects will be deleted.