In Operations Manager 2007, all hardware, software, services, and other logical components that you want Operations Manager to be aware of are described in a model. A model is a computer-consumable representation of software or hardware components that captures the nature of the components and the relationships between them. For example, monitoring messaging services involves monitoring a variety of components such as mailbox servers, front-end servers, operating system components, disk subsystems, Domain Controllers, or DNS servers. Fully monitoring messaging services also requires discovering and monitoring the interaction between these systems, such as monitoring whether e-mail is flowing through the system.

Operations Manager uses management packs to model and monitor software and hardware components. In Operations Manager, management packs contain the models required for the software to interpret the structure of an application and determine the health of the application. This knowledge is expressed as an XML document using a pre-defined XML scheme understood by Operations Manager. Although XML is the language of model-based design, you do not need to know or use XML to use Operations Manager. Familiarity with XML is only required for authoring management packs.

Model-based design uses this standard specification language to tell System Center Operations Manager about important elements of your application or component. Model-based design is important because it allows service-level monitoring instead of only computer-based or hardware-based monitoring. Objects in your model can represent hardware components, such as whether a router is running, or they can represent software, such as whether a particular application or service is running. By combining different objects and relationships, you can create a distributed application model that spans different components, applications, and hardware. Understanding models helps you make the best use of Operations Manager 2007.

To understand models and the process of modeling, consider the analogy of modeling buildings. Start by considering the types of buildings that exist.

Create a model by determining the essence of the object that is being modeled. That is, create something describing the type of object you want to model. If you are familiar with object-oriented modeling or object-oriented programming, this is the same as creating a new class. In Operations Manager, use targeting to direct Operations Manager to apply rules to a specific class or type of object. Targeting is discussed in more detail in Changes Between Microsoft Operations Manager 2005 and Operations Manager 2007.

There are many different kinds of buildings: office buildings, apartment complexes, single-family homes, and factories. Because you are considering modeling buildings, start with what all buildings have in common. For example, the most general type of building can be described as an object with four walls and a roof.

Specialization and Attributes

To describe more types of buildings than a generic building, we need to create more specialized classes. Suppose a generic building has the following attributes:

• Address
  
  
• Construction date
  
  
• Number of floors
  
  
• Square feet
  
  

The address attribute is particularly important, because it is a key attribute. An attribute is called a key attribute when it uniquely identifies a specific object, such as a building. Most buildings cannot be uniquely identified by the construction date, number of floors, or number of square feet.

However, this generic building probably is not detailed enough to model a specific building, such as Microsoft building 7. To create a class that describes an office building, you include not only all the attributes of a generic building, but also the following attributes:

• Employee capacity
  
  
• Number of meeting rooms
  
  

To model a residential building instead of an office building, you need a different set of attributes than the office building attributes. Consider a simplified world where residential buildings are one of two classes: apartment complexes, consisting of multiple apartment units, and single-family residences. An apartment complex might add an attribute for "number of units" to the generic building, although a single family house might add an attribute for "is detached." Both apartment complexes and single-family residences have all the attributes of a generic building, but they do not have the extra attributes of an office building. This property is called specialization or inheritance. In this example, the apartment complex and the single-family both inherit attributes from a residence, but they do not inherit attributes from each other.

In Operations Manager, there are many different types, starting with the most generic Entity class (analogous to the generic building class). Classes become more and more specialized to describe more and more specific things. For example, an Active Directory Domain Controller Computer Role (a class defined in the Active Directory management pack) is a more specialized type of Windows Computer Role object. A Windows Computer Role is a more specialized Logical Entity, which is, in turn, a more specialized Entity.

You do not need to see the inheritance tree for day-to-day operations. Therefore, it is somewhat hidden in the console. However, if you are interested in seeing what the model looks like, you can find it in the Distributed Application Designer.

1. In the Operations Console, click Authoring.

2. On the left pane, click Distributed Applications.

3. Click Create a new distributed application located above the Distributed Applications pane.

4. Fill in a temporary name, select a template, and then click OK.

5. Click Add Component.

6. In the Create New Component Group window, click All Objects.

7. When you are finished exploring the specification tree, click Cancel.

8. Close the Distributed Application Designer, and then click No to avoid saving the temporary application you created.

If you open it immediately after you install Operations Manager, you see nothing about Active Directory or Exchange. However, as you add management packs, more classes are added to the tree. Consider what the model looks like after the Exchange and Active Directory management packs have been imported:

Notice that Operations Manager starts with the most general item, an Entity, and gradually describes more specialized objects. For example, an Active Directory Domain Controller Computer Role is further specialized into an Active Directory 2000 Domain Controller Role and an Active Directory 2003 Domain Controller Role. Each of these share properties of a Domain Controller but have properties that are specific to the different versions of Active Directory.