SNOW-CSA Database Administration and CMDB — 30 Questions

Question 1

A ServiceNow administrator notices that a CI record in the CMDB is not being updated by a scheduled discovery job. The CI is a Linux server that is reachable on the network. Which is the most likely cause?

Accepted Answer

The CI is classified under a different CI class in the CMDB.. When a CI is classified under a different CI class in the CMDB, the scheduled discovery job may not update it because discovery uses the IRE to match incoming data against existing CIs based on identification rules. If the CI's class differs from what the discovery payload expects, the IRE may fail to reconcile the record, or the update may be directed to a different class table, leaving the original CI unchanged. This is a common cause of apparent update failures when the CI is reachable and the discovery source is correctly configured.

Answer

The discovery source is not configured for this IP range.

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The Identification and Reconciliation Engine (IRE) is disabled.

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The cmdb_ci table ACL is set to private.

Question 2

A consultant is designing the CMDB for a large enterprise. The company wants to track relationships between business services, applications, and infrastructure components. Which relationship model should be used to represent that a business service depends on an application, which in turn depends on a server?

Accepted Answer

Dependency relationship (structural). A dependency relationship (structural) is the correct model because it explicitly captures the directional 'depends on' nature of the chain: a business service relies on an application, which in turn relies on a server. In ServiceNow CMDB, structural dependency relationships (e.g., 'Depends on' or 'Used by') are designed to represent these hierarchical, transitive dependencies between CIs, enabling impact analysis and root cause mapping.

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Membership relationship

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Ownership relationship

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Connectivity relationship

Question 3

During a CMDB health review, an administrator finds that many CI records have the same serial number but different names and IP addresses. What is the most likely root cause?

Accepted Answer

The identification rule for the CI class does not include the serial number.. The correct answer is C because the identification rule determines which fields are used to uniquely identify a CI. If the serial number is not included in the identification rule, the CMDB cannot detect duplicates based on serial number, allowing multiple CIs with the same serial number but different names and IP addresses to be created. This is a common misconfiguration that leads to CI proliferation and data inconsistency.

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The CMDB has a scheduled job that deletes old CIs.

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The CI class has a unique constraint on the name field.

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The reconciliation rule is set to 'Create' instead of 'Update'.

Question 4

Which TWO of the following are valid CI relationship types in ServiceNow?

Accepted Answer

Member of. Option C is correct because 'Member of' is a predefined CI relationship type in ServiceNow's CMDB, used to indicate that a CI belongs to a group or cluster, such as a server being a member of a cluster. This relationship is part of the standard CMDB relationship model and is commonly used for grouping CIs like applications, clusters, or business services.

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Uses

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Connects to

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Owns

Question 5

Which THREE of the following are required for ServiceNow Discovery to successfully populate the CMDB?

Accepted Answer

Valid credentials for the target devices. Valid credentials (Option B) are required because ServiceNow Discovery uses SNMP, SSH, WMI, or REST to probe target devices. Without correct credentials, the MID Server cannot authenticate to the device, so it cannot read configuration data or populate CI attributes in the CMDB.

Answer

The CMDB CI tables with open ACLs

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The Identification and Reconciliation Engine (IRE) enabled

Question 6

A company wants to ensure that only authorized changes to the CMDB are allowed. Which THREE of the following mechanisms can help enforce this?

Accepted Answer

CMDB Health Definitions with remediation tasks. Option B is correct because CMDB Health Definitions can include remediation tasks that automatically or manually enforce compliance by correcting unauthorized changes to CI attributes. These tasks are triggered when a health score falls below a threshold, ensuring that only authorized modifications persist in the CMDB.

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The Identification and Reconciliation Engine (IRE)

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Scheduled Discovery jobs

Question 7

An administrator runs a CMDB health report for the CI class cmdb_ci_server and sees the exhibit. Which attribute is the highest priority to populate first?

Accepted Answer

Serial number (serial_number). The CMDB health report shows that the serial_number attribute has the lowest population percentage (e.g., 45%) compared to other attributes. Serial numbers are critical for hardware asset identification, warranty validation, and integration with external asset management systems. Populating serial_number first ensures accurate CI identification and reduces duplicate or orphaned records, which is a foundational step in CMDB data quality.

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Operating system (os)

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Model ID (model_id)

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Manufacturer

Question 8

An administrator inspects the IRE log and sees the exhibit. The IRE created a new CI despite finding a match on serial_number. What is the most likely reason?

Accepted Answer

The identification rule for cmdb_ci_server does NOT include serial_number.. Option C is correct because the IRE uses identification rules to determine which attributes are used for matching CIs. If the identification rule for cmdb_ci_server does NOT include serial_number, then even though a match on serial_number exists, the IRE will not consider it a match and will create a new CI. The IRE only reconciles based on the attributes defined in the identification rule.

Answer

The identification rule for cmdb_ci_server includes serial_number.

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The IRE is configured to always create new records regardless of matches.

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The existing CI has a different name, so IRE considers it a different CI.

Question 9

An administrator wants to ensure that when a user deletes a CI, all its relationships are also deleted to maintain data integrity. What should the administrator configure?

Accepted Answer

A cascade delete rule on the relationship table. Option A is correct because a cascade delete rule on the relationship table (sys_cmdb_rel_ci) ensures that when a CI is deleted, all associated relationship records are automatically removed. This maintains referential integrity in the CMDB without requiring custom scripting or manual cleanup.

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An ACL that denies delete unless relationships are removed first

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A CMDB health rule that flags orphaned relationships

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A business rule on the CI table that deletes relationships on delete

Question 10

A company is using multiple data sources (Discovery, SCCM, and manual imports) to populate the CMDB. They notice that some CI attributes are being overwritten incorrectly. Which feature should be used to define which data source is authoritative for specific attributes?

Accepted Answer

Identification and Reconciliation Engine (IRE) with reconciliation rules. The Identification and Reconciliation Engine (IRE) with reconciliation rules is the correct feature because it allows administrators to define which data source is authoritative for specific CI attributes. When multiple sources populate the CMDB, reconciliation rules determine the priority of data sources, ensuring that attributes from a higher-priority source overwrite those from lower-priority sources, preventing incorrect overwrites.

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CMDB Data Source rules

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Import set transform maps

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Business rules with condition on source field

Question 11

An administrator discovers that a scheduled discovery job is creating duplicate CI records for the same physical server. The server has two IP addresses (one for management, one for production). What is the most likely cause?

Accepted Answer

The identification rule for the CI class does not include a unique hardware identifier like serial number.. Option C is correct because ServiceNow's CMDB uses identification rules to determine whether a discovered CI is new or matches an existing record. For a physical server with multiple IP addresses, the identification rule must include a unique hardware identifier such as a serial number (e.g., from SMBIOS) to prevent duplicate CIs. Without that, the system may treat each IP address as a separate CI, even though they belong to the same server.

Answer

The discovery schedule is set to run too frequently.

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The discovery job is configured to scan only the management IP.

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The server has too many IP addresses for discovery to handle.

Question 12

What is the purpose of the CMDB Health Dashboard?

Accepted Answer

To monitor the completeness and compliance of CI data in the CMDB. The CMDB Health Dashboard is designed to monitor the completeness and compliance of Configuration Item (CI) data within the CMDB. It provides metrics and visualizations that help administrators identify data quality issues, such as missing mandatory fields, stale CIs, or violations of CMDB rules, ensuring the CMDB remains a reliable source of truth for IT operations.

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To manage user roles and permissions for CMDB

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To visualize relationships between CIs

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To configure discovery schedules and probes

Question 13

A large financial institution uses ServiceNow CMDB to manage their IT infrastructure. They have a complex environment with multiple data sources: Discovery, SCCM, and a custom integration from their cloud provider. The CMDB contains over 100,000 CIs. Recently, the CMDB team noticed that for a specific set of Windows servers, the 'os_version' attribute is being updated to an incorrect value every night. The value comes from the SCCM integration, which is supposed to be the authoritative source for software-related attributes. However, the 'os_version' attribute should be authoritative from Discovery. The IRE is configured with reconciliation rules, but the issue persists. The team also finds that the Discovery job for these servers runs at 2:00 AM, and the SCCM integration runs at 3:00 AM. The incorrect value appears after the SCCM run. The reconciliation rules are set so that Discovery is authoritative for 'os_version', but the SCCM integration still overwrites it. What is the most likely cause and recommended action?

Accepted Answer

Review and correct the reconciliation rule to ensure Discovery is the authoritative source for 'os_version' and that the rule is active.. Option D is correct because the reconciliation rule is the mechanism that dictates which data source is authoritative for a specific attribute. If the rule is misconfigured, inactive, or not properly scoped, the IRE will allow the SCCM integration to overwrite the 'os_version' attribute even though Discovery is intended to be authoritative. Reviewing and correcting the rule ensures that the IRE enforces the correct source priority for that attribute.

Answer

Enable the IRE 'Strict' mode to prevent any updates from non-authoritative sources.

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Disable the SCCM integration for these servers and rely solely on Discovery.

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Change the order of the integrations so that SCCM runs before Discovery.

Question 14

A company uses ServiceNow CMDB and wants to ensure that CI attribute updates from a discovery tool are not overwritten by manual changes made by administrators. Which configuration best achieves this?

Accepted Answer

Configure the 'Preserve manual changes' setting in the CMDB CI Class Manager.. Option C is correct because the 'Preserve manual changes' setting in the CMDB CI Class Manager ensures that when a CI attribute is manually updated by an administrator, subsequent discovery runs will not overwrite that specific attribute. This setting works at the class level and compares the source of the last update; if the source is 'Manual', the attribute is preserved even if the discovery tool reports a different value. This directly addresses the requirement to prevent discovery from overwriting manual changes without disabling discovery entirely.

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Set the CI source to 'Manual' to prevent discovery updates.

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Create a business rule to prevent updates from discovery.

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Disable the reconciliation process for the affected CIs.

Question 15

An organization is planning to implement CMDB for a large-scale environment with multiple data sources. They need to ensure that the most trustworthy data source takes precedence when conflicts occur. Which feature should they use?

Accepted Answer

Data Source Priority. Data Source Priority (Option D) is the correct feature because it allows administrators to define a hierarchy of data sources in the CMDB, ensuring that when multiple sources provide conflicting attribute values for the same CI, the source with the highest priority (lowest numeric value) is trusted and its data is used. This directly addresses the requirement to make the most trustworthy data source take precedence in a large-scale, multi-source environment.

Answer

Identification & Reconciliation engine

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Reconciliation

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Set source precedence in the CI class manager for each CI

Question 16

A CMDB administrator notices that duplicate CIs are being created for the same server from different discovery sources. What is the most likely cause?

Accepted Answer

The identification rules for the CI class are not correctly defined.. Duplicate CIs occur when multiple discovery sources (e.g., Service Mapping, Discovery, or cloud APIs) identify the same server but the identification rules fail to reconcile them into a single CI. Identification rules define which attributes (such as serial number, MAC address, or FQDN) uniquely identify a CI class. If these rules are missing, incomplete, or incorrectly prioritized, the system treats each discovery event as a new CI, leading to duplicates.

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The 'Prevent duplicates' flag is not enabled.

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The reconciliation rules are misconfigured.

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The CMDB is set to read-only mode.

Question 17

Which TWO statements about ServiceNow CMDB identification and reconciliation are correct?

Accepted Answer

The Identification and Reconciliation (IRE) engine processes incoming CI data.. Option B is correct because the Identification and Reconciliation (IRE) engine is the ServiceNow component responsible for processing incoming CI data from sources like Discovery, Service Mapping, or integrations. It applies identification rules to determine if a CI already exists and reconciliation rules to resolve attribute conflicts, ensuring data integrity in the CMDB.

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The 'Source' field on a CI can be set per attribute.

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Reconciliation rules are used to identify duplicate CIs.

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The CMDB automatically deletes duplicate CIs when detected.

Question 18

Based on the exhibit, why did the identification rule fail?

Accepted Answer

The serial_number field is empty, but the rule requires it to be non-empty.. The identification rule fails because the serial_number field, which is defined as a required identifier field in the rule configuration, is empty in the incoming payload. ServiceNow CMDB identification rules use a set of fields to uniquely identify CI records; if any required field is missing or null, the rule cannot match or create a record, resulting in a failure. In this case, the payload contains the serial_number field but with no value, which the rule treats as a violation of its non-empty constraint.

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The name field is missing from the payload.

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The rule has a dependency that is not satisfied.

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The ip_address field is not included in the identification rule.

Question 19

Your organization has implemented ServiceNow CMDB with multiple data sources including ServiceNow Discovery, SCCM, and manual imports. You notice that for a critical group of Windows servers, the 'os_version' attribute is being overwritten frequently. Upon investigation, you find that Discovery reports the correct version, but SCCM imports an older version that overwrites it. The Discovery source runs daily at 2 AM, and SCCM imports run at 4 AM. Currently, all data sources have equal priority. You need to ensure that the Discovery value is the authoritative source for os_version on these servers, but you do not want to block SCCM from updating other attributes. What is the best course of action?

Accepted Answer

Create a reconciliation rule that gives Discovery higher priority than SCCM for the os_version attribute on the Windows Server CI class.. Option D is correct because reconciliation rules allow you to define attribute-level priority between data sources without blocking SCCM from updating other attributes. By creating a rule that gives Discovery higher priority than SCCM specifically for the os_version attribute on the Windows Server CI class, Discovery's value will be authoritative for that attribute while SCCM can still update other attributes. This approach preserves the multi-source CMDB integrity without disabling reconciliation or removing SCCM entirely.

Answer

Remove SCCM as a data source for these servers.

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Disable reconciliation for the Windows Server CI class.

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Set the 'Preserve manual changes' flag on the CI class.

Question 20

A company's CMDB has been populated with configuration items (CIs) from various discovery sources. However, when querying the CMDB for all Windows servers, the result set is missing some servers that are known to exist. The administrator has verified that the servers are discovered and appear in the discovery logs. What is the most likely cause of this issue?

Accepted Answer

The missing servers are classified under a different CMDB class than the one being queried.. Option D is correct because the CMDB organizes CIs into a hierarchical class structure (e.g., cmdb_ci_server, cmdb_ci_win_server). If a Windows server is classified under a different parent class (e.g., cmdb_ci_linux_server due to misclassification or a custom class), a query filtering specifically on the Windows server class will exclude it. Discovery populates the CI with the correct class based on the identification and classification rules, but manual reclassification or an incorrect identification rule can place the CI in a different class, making it invisible to class-specific queries.

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The missing servers are duplicates and have been merged into other CIs.

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The missing servers have a status of 'Retired' in the CMDB.

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The user running the query does not have the cmdb_read role.