SERVICENOW-CIS-DISCOVERY Discovery Pattern Design Practice Test 6 — 15 Questions

Question 1

When a pattern step executes an external script (e.g., Python), how can you ensure the pattern waits for the script to finish before proceeding to the next step?

Accepted Answer

The pattern automatically waits for the step process to return. ServiceNow patterns are synchronous by default; the pattern engine waits for each step to return a status (Success/Failure) before moving to the next step.

Answer

Use an asynchronous flag in the script

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Configure the MID Server to process sequentially

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Add a Wait step

Question 2

Which TWO of the following are valid parsing strategies available in the Pattern Designer when processing data retrieved from a device?

Accepted Answer

JSON. The Pattern Designer supports various parsers including 'Delimited' (for tables) and 'JSON' (for object data).

Answer

SQL Query

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SOAP Envelope

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Binary Stream

Question 3

Which TWO steps are essential for parsing a command output that contains key-value pairs formatted as 'key = value'?

Accepted Answer

Define the Line Delimiter. For key-value parsing, identifying the line delimiter and the key-value separator is essential.

Answer

Execute an external shell script

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Convert the output to XML

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Apply a JSON Path

Question 4

Which THREE common challenges arise when using Regex to extract data from command outputs in patterns?

Accepted Answer

Potential for catastrophic backtracking on large strings. Option A is correct because certain regex patterns with nested quantifiers can trigger catastrophic backtracking, causing exponential runtime on large command outputs. Option C is correct because command output formats can change across software versions or configurations, silently breaking patterns that were tightly coupled to the old layout. Option E is correct because long, complex regex strings are hard to read, document, and maintain, especially when they encode many assumptions about output structure. Option B is wrong because regex engines widely support capture groups (e.g., parentheses in PCRE, Python re, and .NET). Option D is wrong because regex is a pattern-matching language and is never automatically converted to JSON.

Answer

Regex does not support capture groups

Answer

Regex is automatically converted to JSON

Question 5

You are building a ServiceNow Discovery pattern for a Linux server that hosts multiple network interfaces. During pattern execution, you need to populate the CI's 'IP Address' field with the IP address of the interface that has the default route. The pattern step that runs the command 'ip route get 8.8.8.8' returns output similar to: '8.8.8.8 via 192.168.1.1 dev eth0 src 192.168.1.100'. You want to reliably extract only the source IP (192.168.1.100) and assign it to the CI attribute. Which pattern step type and configuration should you use?

Accepted Answer

Use a 'Parse' step with a regular expression that captures the 'src' IP, then map the captured group to the CI attribute.. The correct solution extracts the source IP from the command output using a Parse step with a regex that captures the value after 'src'. This ensures the CI attribute receives only the valid IP address associated with the default route. Other options either assign incorrect data or fail to isolate the required token, leading to inaccurate CI records.

Answer

Use a 'Parse' step with a regex that captures the entire line, then assign the whole line to the CI attribute.

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Use a 'Command' step to run 'hostname -I' and assign its output directly to the CI attribute.

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Use a 'Condition' step to check if the output contains 'src', then use a 'Set Attribute' step to assign the first IP found in the output.

Question 6

You are designing a Discovery pattern for a network switch. You need to create a CI Relationship between the switch and its connected devices. In the Pattern Designer, which step type should you use to create this relationship?

Accepted Answer

Create Relation. To create a CI Relationship during Discovery, you must use the Create Relation step. This step allows you to define the relationship type and link the two CIs. Other steps like Create CI, Parse Variable, and Identification serve different purposes and cannot establish relationships.

Answer

Parse Variable

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Create CI

Answer

Identification

Question 7

You are designing a pattern to discover Linux servers. You need to ensure that the pattern only runs the 'Identify' step if the server's hostname matches a specific naming convention (e.g., starts with 'prod-'). Which Pattern Designer feature should you use to implement this conditional logic?

Accepted Answer

Step condition. To conditionally execute a specific step, you must use a step condition. This allows you to define logic that evaluates pattern variables or other data to determine if the step should run. Preconditions apply to the whole pattern, while debug mode and Parse Variable serve different purposes.

Answer

Debug mode

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Pattern precondition

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Parse Variable

Question 8

A discovery pattern must ensure that a CI is only created (not updated) when the identification process cannot find an existing record. The pattern currently has an Identification step that runs successfully. You need to configure the next step to execute only if the CI was not found. Which condition should you use in the step's 'Run if' condition?

Accepted Answer

Set the condition to '${ci.sys_id}' is empty. The Identification step populates the pattern's CI context with the sys_id of a matched CI. If no match is found, that sys_id remains empty. Therefore, to run a step only when no CI exists, the condition must check that the sys_id is empty. This prevents duplicate CI creation and ensures the pattern follows the intended create-only logic.

Answer

Set the condition to '${ci.sys_id}' != null

Answer

Set the condition to '${identification.status}' == 'found'

Answer

Set the condition to '${ci.sys_id}' is not empty

Question 9

You are designing a pattern to discover Windows servers. You need to collect the installed software list. The command output is a large text block with multiple lines, each containing a software name and version separated by a tab. Which parsing strategy in the Pattern Designer is best suited for this data?

Accepted Answer

Delimited Text. Delimited Text parsing is the most appropriate for tab-separated values. It splits each line into fields based on the delimiter, allowing straightforward extraction of software names and versions. Regular expressions, XML, and JSON are unnecessary or incorrect for this data format.

Answer

JSON

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Regular Expression

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XML

Question 10

A pattern designer is creating a pattern to discover a Linux server. The pattern needs to extract the operating system version from the output of the 'uname -a' command. The output format varies slightly across distributions. Which parsing strategy should be used to reliably extract the version?

Accepted Answer

Regular expression. Regular expressions are the most reliable way to extract data from command output that may have variable formatting. They allow pattern matching around the target data, ignoring surrounding inconsistencies. XML and JSON parsing require structured data, and delimiter-based parsing assumes consistent field positions, which is not the case here.

Answer

XML parsing

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JSON parsing

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Delimiter-based parsing

Question 11

You are creating a new Discovery pattern for a custom application. You need to define the pattern's entry point and specify which CI type it will discover. Where in the Pattern Designer do you configure the CI type that the pattern will create or update?

Accepted Answer

Pattern properties. The CI type that a pattern discovers is defined in the pattern properties. This setting is crucial because it determines the CMDB class for the CI records created or updated by the pattern. Other areas like step conditions, Parse Variable settings, and Create CI steps do not define the overall CI type.

Answer

Step conditions

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Create CI step

Answer

Parse Variable settings

Question 12

A pattern includes a step that runs a command to retrieve a list of installed software. The command output is large and needs to be processed to create multiple CI records. Which pattern step type should be used to iterate over each line of output and create a CI for each?

Accepted Answer

For each step. The for each step is specifically designed to iterate over a collection of items and execute a set of steps for each one. This allows the pattern to process each line of software output and create a CI for each entry. Other step types do not provide iteration capabilities.

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Parallel step

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Conditional step

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Parse step

Question 13

You are designing a Discovery pattern that runs a command on a Linux host and then parses the output to populate the 'CPU core count' field on the CI. The command's output contains multiple lines, and the relevant number appears on the same line as the label 'CPU(s):'. Which Pattern Designer step configuration should you use to reliably extract the numeric value?

Accepted Answer

Use a 'Parse Variable' step with a regular expression that captures the digits after 'CPU(s):'.. When a value is embedded in a labeled line, a regex-based Parse Variable step is the reliable extraction method because it isolates the capture group independent of line position or surrounding whitespace. Static assignment, table parsing, and whole-line iteration each fail to produce a clean numeric value for the CI attribute in this scenario.

Answer

Use a 'Get Next' step to iterate through lines until one contains 'CPU(s):' and then write that entire line to the CI.

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Use a 'Parse Table' step configured with the column header 'CPU(s):' and a single row.

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Use a 'Set Parameter' step with a static value of 'CPU(s):' and reference the line index.

Question 14

A pattern designer wants to reuse a set of steps that are common across multiple patterns, such as steps to gather basic system information. What should the designer do to avoid duplicating these steps in each pattern?

Accepted Answer

Create a new pattern that contains the common steps and then reference it from other patterns using a 'Pattern' step.. The 'Pattern' step in ServiceNow Discovery allows one pattern to invoke another, enabling modular design. By extracting common steps into a reusable pattern, you avoid duplication and simplify updates. This is the standard method for sharing pattern logic across multiple discovery patterns.

Answer

Define the common steps as a 'Subflow' in Flow Designer and call it from the pattern.

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Copy and paste the steps into each pattern and maintain them separately.

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Use the 'Include' directive in the pattern XML to import steps from a library.

Question 15

You are building a pattern for a network device that exposes data only through an SSH session requiring a non-standard prompt and a two-step authentication exchange. Your pattern must run several commands after login and parse each result. Which approach correctly addresses the interactive login and command execution within the pattern?

Accepted Answer

Configure the pattern's connection section with the SSH credentials, set the prompt pattern to match the device's custom prompt, and add command steps that execute after the session is established.. Interactive SSH devices with custom prompts are handled by configuring the pattern's connection with credentials and a prompt match, then issuing command steps inside that session. Separate patterns, concatenated commands, or unrelated protocols like WMI and SNMP cannot establish or maintain the required interactive SSH session for sequential command execution and parsing.

Answer

Set the connection type to 'WMI' and provide the device's SNMP community string so the MID Server can retrieve the data without an interactive login.

Answer

Use a single 'Run Command' step with all commands concatenated by semicolons and parse the combined output with one regex.

Answer

Create separate patterns for each command and rely on the MID Server's automatic session reuse to keep the SSH connection alive across pattern runs.