ASL and the MODEL language
In order to create adapters that
interact with a
Domain Manager
, it is necessary to understand how the Domain Manager
is configured. The adapter creates, deletes, and interacts
with instances of objects that are defined by using the MODEL language. The MODEL language is
an object-oriented language used to construct a correlation model to describe a managed domain. The language is used to define a set of classes and the attributes, relationships, and events that are associated with the classes.
Classes describe
the objects that are modeled for use in a
Domain Manager
. Instances are specific occurrences of a class. For example, a class might describe a human and
an instance of the class is someone named Bill.Attributes describe a class and, for an instance of the class, include information about its present state. Examples of attributes include an element’s name and a counter
that counts the number of packets traversing an interface.
Relationships define how instances are related to other instances. Relationships can be one-to-one, one-to-many, many-to-one, or many-to-many. When only a single
instance can be related to another instance (or instances), it is a relationship. When multiple instances can be related to another instance (or instances), it is a relationshipset.
Events describe the failures that
can occur for a class, the symptoms that these failures can cause, and the effect of failures.
Symptoms can be described a follows:
- Local, meaning they are observed in the instance of the class.
- Propagated, meaning they are observed in instances related to the failing instances.Once classes are specified, the model is loaded and run on aDomain Manager. Instances are created for each entity that is modeled. Each instance is associated with a class and has values for its attributes, relationships, and events.The models stored in aDomain Managerare static. Instances are dynamic and are stored in the repository, as shown in Domain Manager with a model and repository.Instances in aDomain Managerconsist of a table entry and data. The table entry includes the name of each instance and its class. Each instance name must be unique. The table of names always contains an entry for the NULL object.The data associated with each instance includes properties such as attributes, operations, and the relationships between instances. The data also includes event information such as problems, symptoms, and events.TheMODEL Reference Guideprovides additional information about MODEL.Domain Manager with a model and repository
