Configuration Management Database
About 15% of the CIS-SM exam — see all 6 domains.
Service Mapping is both a producer and a consumer of the CMDB, so the exam expects fluency in the data model.
Application services in the CMDB and CSDM
The Common Service Data Model (CSDM) is ServiceNow's standard for organizing service data in the CMDB. Service Mapping populates the application service record (cmdb_ci_service_auto / service tables) and the relationships beneath it. Under CSDM, the application service is the central technical-service construct; it can be associated upward with business-facing services (a business service offering Depends on::Used by the application service) and downward with the CIs that compose it. Knowing how CSDM concepts map to CMDB tables, and that Service Mapping output is meant to populate the technical/application service layer, is a frequent exam target.
CI relationships
Service Mapping's value is the relationships (dependency edges) it creates between CIs. These relationships drive impact analysis, dependency views, and Event Management impact calculations. The relationship direction (depends on / used by) matters for how impact propagates.
Grouping and dynamic membership
- CMDB groups collect CIs for management and operations.
- Dynamic CI groups define membership by query so the group self-updates as the CMDB changes, the same mechanism that can populate an application service.
- Tags (notably from cloud providers) can drive both discovery scope and service membership.
Data quality
Accurate maps require a healthy CMDB: correct CI identification (so CIs are not duplicated), good reconciliation (so the authoritative source wins on each attribute), and clean class assignment. Poor identification produces duplicate or mismatched CIs and broken maps, which is why CMDB health is treated as a prerequisite to a successful Service Mapping deployment.
Fast-recall: Domain 5
- Service Mapping populates the application service layer of the CMDB, aligned to CSDM.
- Know how CSDM concepts map to CMDB tables; application service is the central technical construct.
- The relationships it creates drive impact analysis and dependency views; direction matters.
- CMDB groups, dynamic CI groups (query-based, self-updating), and tags organize membership.
- CMDB health (identification + reconciliation) is a prerequisite for good maps.
Sample questions from this domain
Three of the 45 in this domain, with the reasoning. The full set is in the question bank.
What does the CMDB Identification and Reconciliation Engine (IRE) primarily prevent?
- A. Duplicate CIs by applying identification rules before insert/update ✓
- B. Classification errors, by choosing the CI class for each discovered device
- C. Stale CIs, by retiring records that Discovery has not updated recently
- D. Orphaned relationships, by deleting cmdb_rel_ci rows whose CIs are retired
Why: The Identification and Reconciliation Engine applies identification rules to each incoming payload so it matches an existing CI instead of inserting a duplicate, and its reconciliation rules then govern attribute updates. Choosing the CI class is classification, which Discovery performs before IRE is involved. Retiring CIs that have not been updated is a lifecycle task handled by CMDB Data Manager policies, not by IRE. IRE does not delete relationship rows in cmdb_rel_ci; relationship cleanup is a separate data management concern.
In IRE, what is an identification rule?
- A. A defined set of identifier criteria (attributes) used to uniquely match a CI of a given class ✓
- B. A rule that decides which data source is allowed to update each attribute of a CI in that class
- C. A classifier that maps probe output to the CI class a discovered device belongs to
- D. A data refresh rule that sets how long a source's attribute values remain current
Why: An identification rule holds one or more identifier entries, each listing the criterion attributes that uniquely match a CI of its class, and IRE uses it to match incoming data to existing records. Deciding which data source may update an attribute is the job of a reconciliation rule. Mapping probe output to a CI class is what a Discovery classifier does, before identification. A data refresh rule defines when a source's data is considered stale; it does not define uniqueness.
What is the CI Class Manager used for?
- A. Running horizontal Discovery schedules and reviewing the classification results by class
- B. Managing CMDB classes, their attributes, identification rules, and relationships in one interface ✓
- C. Building the probes and sensors that populate each class's attributes during discovery
- D. Mapping application services by following connections from an entry point to each class
Why: CI Class Manager is the single interface for the CMDB class hierarchy: class attributes, identification and reconciliation rules, suggested relationships and dependent relationship rules. Discovery schedules are created and run from the Discovery application, not from CI Class Manager. Probes, sensors and patterns that collect attribute values are built in Discovery and Pattern Designer. Following connections from an entry point is what Service Mapping does when it maps an application service.