AIX 5L Problem Determination - IBM Redbooks

either be a superclass or a subclass. The main difference between superclasses
and subclasses is the resource control (shares and limits):
► At the superclass level, the determination of resource entitlement (based on
the resource shares and limits) is based on the total amount of each resource
managed by WLM available on the machine.
► At the subclass level, the resource shares and limits are based on the amount
of each resource allocated to the parent superclass.
The system administrator (the root user) can delegate the administration of the
subclasses of each superclass to a superclass administrator (a non-root user),
thus allocating a portion of the system resources to each superclass and then
letting superclass administrators distribute the allocated resources among the
users and applications they manage.
WLM supports 32 superclasses (27 user-defined plus five predefined). In turn,
each superclass can have 12 subclasses (10 user-defined and two predefined,
as shown in Figure 10-4). Depending on the needs of the organization, a system
administrator can decide to use only superclasses or both superclasses and
subclasses. An administrator can also use subclasses only for some of the
superclasses.
Each class is given a name by the WLM administrator who creates it. A class
name can be up to 16 characters long and can only contain uppercase and
lowercase letters, numbers, and underscores (_). For a given WLM configuration,
the names of all the superclasses must be different from one another, and the
names of the subclasses of a given superclass must be different from one
another. Subclasses of different superclasses can have the same name. The
fully qualified name of a subclass is superclass_name.subclass_name.
In the remainder of this section, whenever the term class is used, it is applicable
to both subclasses and superclasses. The following subsections describe both
super and subclasses in greater detail, as well as the backward compatibility
WLM provides to configurations of its first release.
Superclass Superclass Superclass
subclass
Figure 10-4 Hierarchy of classes
subclass subclass
Chapter 10. Performance problem determination 277