Impacted Services not populating on alerts in Event ManagementIssue <!-- /*NS Branding Styles*/ --> .ns-kb-css-body-editor-container { p { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } span { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } h2 { font-size: 24pt; font-family: Lato; color: var(--now-color--text-primary, black); } h3 { font-size: 18pt; font-family: Lato; color: var(--now-color--text-primary, black); } h4 { font-size: 14pt; font-family: Lato; color: var(--now-color--text-primary, black); } a { font-size: 12pt; font-family: Lato; color: var(--now-color--link-primary, #00718F); } a:hover { font-size: 12pt; color: var(--now-color--link-primary, #024F69); } a:target { font-size: 12pt; color: var(--now-color--link-primary, #032D42); } a:visited { font-size: 12pt; color: var(--now-color--link-primary, #00718f); } ul { font-size: 12pt; font-family: Lato; } li { font-size: 12pt; font-family: Lato; } img { display: ; max-width: ; width: ; height: ; } } The Impacted Services field on an alert in Event Management is empty or not updating as expected, even though the affected configuration item (CI) is part of a mapped business service topology. Symptoms<!-- /*NS Branding Styles*/ --> .ns-kb-css-body-editor-container { p { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } span { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } h2 { font-size: 24pt; font-family: Lato; color: var(--now-color--text-primary, black); } h3 { font-size: 18pt; font-family: Lato; color: var(--now-color--text-primary, black); } h4 { font-size: 14pt; font-family: Lato; color: var(--now-color--text-primary, black); } a { font-size: 12pt; font-family: Lato; color: var(--now-color--link-primary, #00718F); } a:hover { font-size: 12pt; color: var(--now-color--link-primary, #024F69); } a:target { font-size: 12pt; color: var(--now-color--link-primary, #032D42); } a:visited { font-size: 12pt; color: var(--now-color--link-primary, #00718f); } ul { font-size: 12pt; font-family: Lato; } li { font-size: 12pt; font-family: Lato; } img { display: ; max-width: ; width: ; height: ; } } The Impacted Services column is blank on one or more alerts in the Active Alerts list.The sn_services count on em_alert remains 0 after an alert is created or its CI changes.The Service Dashboard or Service Operations Workspace does not reflect the expected service impact for the alert.Records are missing from the em_impacted_ci or em_impacted_service tables for the affected alert.Impacted services populate for some alerts but not others, even when the associated CIs are in the same topology. Facts<!-- /*NS Branding Styles*/ --> .ns-kb-css-body-editor-container { p { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } span { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } h2 { font-size: 24pt; font-family: Lato; color: var(--now-color--text-primary, black); } h3 { font-size: 18pt; font-family: Lato; color: var(--now-color--text-primary, black); } h4 { font-size: 14pt; font-family: Lato; color: var(--now-color--text-primary, black); } a { font-size: 12pt; font-family: Lato; color: var(--now-color--link-primary, #00718F); } a:hover { font-size: 12pt; color: var(--now-color--link-primary, #024F69); } a:target { font-size: 12pt; color: var(--now-color--link-primary, #032D42); } a:visited { font-size: 12pt; color: var(--now-color--link-primary, #00718f); } ul { font-size: 12pt; font-family: Lato; } li { font-size: 12pt; font-family: Lato; } img { display: ; max-width: ; width: ; height: ; } } Impacted service population is a two-phase process: a background topology pre-computation phase and a per-alert traversal phase. Both must be functioning for impacted services to appear correctly.The em_impacted_graph table stores pre-computed CI-to-business-service paths. If this table is empty or stale, no impact propagation occurs.The em_impacted_ci table stores per-alert impact results and is populated by EvtMgmtCalculateImpactedCis when an alert is created or its CI changes.The em_impacted_service table and the sn_services count on em_alert are maintained by SNC.ImpactManager background jobs — not by the per-alert traversal.The SNC.ImpactManager jobs run every 5 seconds via dynamically created scheduled jobs.The traversal is capped at 10 hops and 10,000 CIs by default. However, the property evt_mgmt.impacted_cis.bypass_limits_for_services defaults to true, which means the system continues upward to find business services even if the CI limit is reached.If the CI on the alert is not set, the traversal does not run.The graph is fed by Service Mapping discovered maps or manually defined CI-to-service relationships in CMDB. If neither is in place, em_impacted_graph will have no relevant data. Release<!-- /*NS Branding Styles*/ --> .ns-kb-css-body-editor-container { p { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } span { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } h2 { font-size: 24pt; font-family: Lato; color: var(--now-color--text-primary, black); } h3 { font-size: 18pt; font-family: Lato; color: var(--now-color--text-primary, black); } h4 { font-size: 14pt; font-family: Lato; color: var(--now-color--text-primary, black); } a { font-size: 12pt; font-family: Lato; color: var(--now-color--link-primary, #00718F); } a:hover { font-size: 12pt; color: var(--now-color--link-primary, #024F69); } a:target { font-size: 12pt; color: var(--now-color--link-primary, #032D42); } a:visited { font-size: 12pt; color: var(--now-color--link-primary, #00718f); } ul { font-size: 12pt; font-family: Lato; } li { font-size: 12pt; font-family: Lato; } img { display: ; max-width: ; width: ; height: ; } } All supported releases. Cause<!-- /*NS Branding Styles*/ --> .ns-kb-css-body-editor-container { p { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } span { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } h2 { font-size: 24pt; font-family: Lato; color: var(--now-color--text-primary, black); } h3 { font-size: 18pt; font-family: Lato; color: var(--now-color--text-primary, black); } h4 { font-size: 14pt; font-family: Lato; color: var(--now-color--text-primary, black); } a { font-size: 12pt; font-family: Lato; color: var(--now-color--link-primary, #00718F); } a:hover { font-size: 12pt; color: var(--now-color--link-primary, #024F69); } a:target { font-size: 12pt; color: var(--now-color--link-primary, #032D42); } a:visited { font-size: 12pt; color: var(--now-color--link-primary, #00718f); } ul { font-size: 12pt; font-family: Lato; } li { font-size: 12pt; font-family: Lato; } img { display: ; max-width: ; width: ; height: ; } } Impacted services on an alert are populated through two sequential, independent phases. A failure or misconfiguration in either phase results in empty or incorrect impacted service data. Phase 1 — Impact graph pre-computation The SNC.ImpactManager Java class runs multiple scheduled jobs (every 5 seconds) that traverse CMDB CI relationships (cmdb_rel_ci) and build the em_impacted_graph table. Each row in this table maps a child CI to a parent CI or business service. If these jobs are not running, or if no CI-to-service relationships exist in CMDB (via Service Mapping or manual definition), the graph will be empty and no impact can be calculated. Phase 2 — Per-alert impact traversal When an alert is created or its CI field changes, EvtMgmtCalculateImpactedCis.calculate(alertGr) is invoked. This method seeds from the alert's CI, clears existing records in em_impacted_ci for that CI, then traverses upward through em_impacted_graph in a breadth-first loop. For each node it reaches: If the parent equals the business service (a leaf row), it is added to the impacted services list.If the parent is an intermediate CI, traversal continues upward. Results are batch-inserted into em_impacted_ci after traversal completes. The ImpactManager background jobs then read em_impacted_ci to update em_impacted_service and the sn_services integer count on the alert record. Common root causes include: em_impacted_graph is empty — no Service Mapping topology exists or CI relationships are not defined in CMDB.The alert's CI field (cmdb_ci) is not set.The master switch property evt_mgmt.impacted_cis.enable is set to false.The ImpactManager scheduled jobs are not running or are stuck.The topology is very large and the traversal hit the CI limit before reaching a business service (less common when bypass_limits_for_services is true). Resolution<!-- /*NS Branding Styles*/ --> .ns-kb-css-body-editor-container { p { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } span { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } h2 { font-size: 24pt; font-family: Lato; color: var(--now-color--text-primary, black); } h3 { font-size: 18pt; font-family: Lato; color: var(--now-color--text-primary, black); } h4 { font-size: 14pt; font-family: Lato; color: var(--now-color--text-primary, black); } a { font-size: 12pt; font-family: Lato; color: var(--now-color--link-primary, #00718F); } a:hover { font-size: 12pt; color: var(--now-color--link-primary, #024F69); } a:target { font-size: 12pt; color: var(--now-color--link-primary, #032D42); } a:visited { font-size: 12pt; color: var(--now-color--link-primary, #00718f); } ul { font-size: 12pt; font-family: Lato; } li { font-size: 12pt; font-family: Lato; } img { display: ; max-width: ; width: ; height: ; } } Work through the following steps to identify and resolve the cause. Verify the alert has a CI assigned.Open the alert record and confirm the Configuration Item (cmdb_ci) field is populated. If it is empty, the per-alert traversal does not run. Ensure the event that created the alert includes a valid CI reference, or update the alert's CI field manually to trigger recalculation. Check whether em_impacted_graph is populated.Navigate to Event Management > Administration and query the em_impacted_graph table, filtering by the alert's CI as child_id. If no rows are returned, the graph has not been built for this CI. This is typically caused by one of the following: Service Mapping has not run or has not discovered the CI.No manual CI-to-service relationships are defined in CMDB for this CI. Confirm the CI is part of a mapped service topology and that Service Mapping has completed successfully. Confirm that evt_mgmt.impacted_cis.enable is set to true.Navigate to sys_properties.list and search for evt_mgmt.impacted_cis.enable. This is the master switch for Phase 2. If it is set to false, per-alert traversal is completely disabled. Set the value to true and save. Verify the ImpactManager scheduled jobs are running.Navigate to System Definition > Scheduled Jobs and search for jobs with ImpactManager in the script. Confirm that the jobs exist, are active, and are executing successfully. These jobs run every 5 seconds and are responsible for updating em_impacted_service and the sn_services count. If the jobs are missing, a system restart or plugin reactivation may be required to recreate them. Review additional tuning properties if the topology is large.The following properties control traversal limits. Review and adjust as needed: PropertyDefaultEffectevt_mgmt.impacted_cis.max_levels10Maximum hops upward through the graphevt_mgmt.impacted_cis.max_cis_limit10000Maximum CIs traversed per calculationevt_mgmt.impacted_cis.bypass_limits_for_servicestrueWhen true, limits are bypassed when looking for business services (only CI traversal is capped)evt_mgmt.impacted_cis.enable_connected_servicestrueWhether traversal continues across service boundaries Note: Ensure evt_mgmt.impacted_cis.bypass_limits_for_services is set to true (the default). This ensures that even when the CI traversal limit is reached in a large topology, the system continues upward specifically to identify business services. Trigger recalculation after resolving the root cause.Once the underlying issue is addressed, update the alert's CI field (even temporarily clearing and resetting it) to trigger EvtMgmtCalculateImpactedCis.calculate() again. After a short delay, the ImpactManager background jobs will pick up the updated em_impacted_ci records and refresh the impacted services data on the alert. 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