Add Expression Overrides

You can use the Add Expression Overrides window to define a situation override to be distributed to one or more managed systems.

A situation override is a set of expressions that can conditionally substitute comparison values that are different from those in the situation formula, and applied to one or more of the managed systems that the situation is distributed to.

The Add Expression Overrides window supports creating expression overrides using specified comparison values. You can also use expression modeling to create the override expression from a calculated baseline value.

Navigation tree

The navigation tree on the left side of the window shows the situation you are currently editing and the assigned managed systems and managed system groups for the situation, with the currently selected entries highlighted. You can click items in this list to change which systems are included in the override.

Reference formula

The Reference formula area shows the original situation formula. This is the formula you are overriding. You can view the reference formula as a table or graphic by clicking the respective Table icon

Table View or Show formula icon

Graphic View tab.

Formula overrides

The Expressions tab is divided into two panes: on the left are attributes that can be applied to the override, but which cannot be used for expression modeling; on the right are attributes whose override values can be modified with expression modeling. Specify the override values to apply to the selected managed systems.

To model override values, click Model Expression (see Model Expression). This feature is most effective for attributes that have historical data collected.
To edit an expression, click in a table cell and edit the values.
- To define a schedule when the override should run, select Click here to assign an override schedule. Select a defined schedule from the list or create a new schedule (see Select Override Expression Schedule).
- The columns in the right-hand section define the comparison values for the expression. These are the values that will be substituted for those in the reference formula if the override condition is met, or if no override condition is set. Click in the appropriate table cells to edit the comparison values used for the override expression.
To add an expression, click Add Expression.
To remove an expression, select the check box next to the expression that you want to remove and click Remove Expression.

The Details tab shows information for the situation override:

Assigned to

The managed systems or managed system groups to which this situation override is currently distributed.

Priority

This field is a display-only field showing the relative priority of this situation override. If multiple overrides are distributed to the same managed system, the priority determines which override takes precedence. This can happen if an override is distributed to an individual managed system, and another override is distributed to a managed system group that includes the same system.

Situation overrides that are distributed to managed systems have a higher priority than overrides distributed to managed systems groups: 1 is the highest priority; 200 is the lowest.

Description

Enter an optional description of the situation override.

Add Expression

Click this button to add a new formula row.

Remove Expression

Select the check box next to the expression you want to delete and click Remove Expression.

Model Expression

Click this button to open the Model Expression dialog.

Restriction:

An override expression cannot add attribute comparisons that do not appear in the reference formula or change the comparison operators used.
If the override contains multiple expressions, each must have a unique override condition.
An override expression must be different from the reference formula (at least one comparison value must be changed).
If you no longer need an expression override definition, you can remove it (in the Add Expression Overrides window, select the check box next to the definition and click Remove Expression). After clicking OK to close the Add Expression Overrides window, you will be unable to edit the situation until it has been refreshed: You can adjust the value in an expression, but you cannot change the formula function or relational operator.