If necessary, create a precondition that defines how Discovery and Service Mapping execute a pattern step.

Before you begin

Role required: pd_admin

Basic knowledge of programming is desirable.

Create a pattern or select a pattern that you want to modify.

Navigate to the relevant pattern step:

  1. On the pattern form, select the relevant identification section for Discovery.

    Alternatively, select the relevant identification or connection section for Service Mapping.

  2. Select the relevant pattern step or click Add a step button to add a step.

About this task

You can define a single or multiple prerequisite conditions. For example, you can define that a step is run only during the horizontal or top-down discovery using the pattern_runtime_mode variable.

If a precondition defined for a shared library step is not fulfilled, the pattern skips all steps belonging to this shared library. For example, if the file, to which the variable points, does not contain "test", the pattern does not run the shared library steps 1-1 to 1-5. The precondition exists only for the pattern within which you created it. The precondition does not affect other patterns using this shared library.
Precondition for a shared library step

Procedure

  1. Click the Precondition check box next to the Operation list.
    Not all operations allow you to use preconditions.
  2. In the first condition field, enter the required value.
    For example, enter the actual string or a variable name.

    Define precondition criteria.
  3. Select an operator from the list.
    If you select Is Empty, the second field is rendered irrelevant and disappears.
  4. To add more conditions, click the plus icon and define the criteria.
  5. If you create multiple conditions, define if this pattern must meet all or any of them: From the Meet list, select All or Any.
  6. Define if the criteria must be satisfied or not for the step operations to run: From the If Condition is list, select True or False.

Example

You create a pattern step to filter data in the cluster string table to receive a table containing only cluster names. You can set a precondition to filter the table only if the cluster string variable is not empty.

Defining the precondition.