Free Practice Questions for ServiceNow CIS-Discovery Exam

The Application Pattern Type is a pattern that discovers applications and their dependencies by using probes and sensors1. It has two main components: the Run Order and the Identification Section2. The Run Order defines the sequence of probes and sensors that Discovery uses to find and classify CIs2. The Identification Section specifies the criteria that Discovery uses to identify CIs and their relationships2. The other options, CI Type and Operating System, are not specific to the Application Pattern Type. They are used for other pattern types, such as the Horizontal Pattern Type and the Service Mapping Pattern Type3 .

References: 1: Application Pattern Type 2: Application Pattern Type components 3: Horizontal Pattern Type : Service Mapping Pattern Type

The image shows a part of a horizontal pattern in Pattern Designer that uses the WMI Query operation to retrieve information about the processes running on a Windows server. The operation takes a WQL query as an input parameter and returns a tabular variable that contains the results of the query. The tabular variable is named ‘WMI Query’ by default, but it can be renamed by the user. The WQL query in the image selects four attributes from the Win32_Process class: Name, MaximumWorkingSetSize, PageFaults, and PeakVirtualSize. These attributes are stored as scalar variables in the tabular variable, and they can be accessed by using the dot notation, such as WMI Query.Name or WMI Query.MaximumWorkingSetSize. Therefore, the most probable results of the image are a tabular variable named ‘WMI Query’ and two scalar variables named ‘MaximumWorkingSetSize’ and ‘PeakVirtualSize’.

References:

Pattern Designer | WMI Query

Win32_Process class

WQL (SQL for WMI)

ServiceNow Discovery can be extended in three main ways: Classifiers, Probes & Sensors, and Discovery Patterns. Classifiers are used to identify the type of device or application that is being discovered, based on the information returned by a probe. Probes are commands or scripts that are executed on the target device or application to collect data. Sensors are scripts that process the data collected by probes and create or update configuration items (CIs) in the CMDB. Discovery Patterns are graphical representations of the discovery process that can be customized or created to discover specific types of devices or applications, using classifiers, probes, and sensors as building blocks.

References:

Discovery overview - Product Documentation: Vancouver - Now Support Portal

Create a Discovery CI classification - Product Documentation: Vancouver - Now Support Portal

Discovery probes and sensors - Product Documentation: Vancouver - Now Support Portal

Discovery patterns - Product Documentation: Vancouver - Now Support Portal

 Reconciliation rules are used to determine which data sources can update CI attributes in ServiceNow. Reconciliation rules can be static or dynamic, and they can be applied to specific CI classes, attributes, or discovery sources. Reconciliation rules can also specify the actions to take when there are unmatched values, such as removing, ignoring, or updating them1.

References:

1: Reconciliation rules - Product Documentation: San Diego - Now Support Portal

A classifier is a set of rules that identifies a device type based on the results of a probe. A classifier can have one or more related lists that define the classification criteria, the pattern probes, and the triggers probes. The pattern probes related list specifies which horizontal discovery pattern to run for the device type. The triggers probes related list specifies which probes to run after the device is classified, and before the horizontal discovery pattern is executed. The triggers probes can be used to gather additional information or credentials that are needed for the horizontal discovery pattern12.

References:

1: ServiceNow Discovery Overview, page 9

2: ServiceNow Discovery Documentation, Classifiers section

In ServiceNow Discovery, a horizontal discovery pattern refers to the logical set of steps that the Discovery process executes to find CI information across the network. Each step in a horizontal discovery pattern performs specific operations such as running probes, executing commands, or querying databases to gather information about the configuration items (CIs). It's about expanding the breadth of discovery across devices and applications, rather than going in-depth into a specific CI's details, which would be vertical discovery. Classifiers, credential depots, and port scanning tools are part of the discovery process but do not describe the horizontal discovery pattern itself.

When increasing the maximum number of threads for a MID Server in ServiceNow Discovery, it's often necessary to also increase the memory allocated to the MID Server application. This is because more threads can result in higher memory usage as each thread may consume resources while performing discovery tasks. Increasing disk space, updating ACL rules for CMDB tables, or increasing the MID Server max payload size are not directly related to the number of threads used by a MID Server. References = ServiceNow Discovery documentation, especially sections discussing MID Server configuration and performance tuning.

The Parse Variable pattern operation allows you to extract information from the output of a previous operation and save it in a variable. You can choose from different parsing methods, such as JSON File, XML File, Regular Expression, or Custom Script. To have two different parsing methods to populate variables, you need to use two different steps, each with a different Define Parsing selection. For example, you can use one step to parse a JSON file and another step to parse an XML file. You cannot use two different parsing methods on the same step, as the Define Parsing selection is unique for each step.

References:

Parse command output: This article explains how to use the Parse command output operation and the different parsing methods available.

Pattern Designer: Parse Variable - JSON File gives error: This article provides a troubleshooting tip for using the JSON File parsing method.

Examples of EVAL scripts used in Discovery patterns: This article provides some examples of custom scripts that can be used for the Custom Script parsing method.