Service Mapping

Service Mapping

Overview

This skill provides a structured approach to managing service maps in ServiceNow ITOM Service Mapping. It covers:

• Discovering and viewing business service topologies
• Validating service map completeness and accuracy
• Identifying unmapped or orphaned CIs that should belong to a service
• Analyzing service dependency chains for impact assessment
• Reviewing and troubleshooting discovery patterns
• Detecting mapping gaps between services and their underlying infrastructure

When to use: When operations or service owners need to understand service topology, validate discovery results, troubleshoot broken service maps, or prepare for change impact analysis.

Plugin required: com.snc.service-mapping

Prerequisites

• Roles: sm_admin, sm_user, itil, or cmdb_read
• Access: Read/write to cmdb_ci_service, svc_ci_assoc, sa_pattern, cmdb_rel_ci
• Knowledge: Familiarity with CMDB CI classes, service mapping concepts, and discovery patterns
• Plugins: com.snc.service-mapping and com.snc.service-watch must be activated

Procedure

Step 1: List Business Services and Their Health

Retrieve all defined business services to understand the service landscape.

Using MCP:

Tool: SN-Query-Table
Parameters:
  table_name: cmdb_ci_service
  query: active=true^ORDERBYname
  fields: sys_id,name,number,operational_status,busines_criticality,owned_by,support_group,sys_class_name,sys_updated_on
  limit: 50

Using REST API:

GET /api/now/table/cmdb_ci_service?sysparm_query=active=true^ORDERBYname&sysparm_fields=sys_id,name,number,operational_status,busines_criticality,owned_by,support_group,sys_class_name,sys_updated_on&sysparm_display_value=true&sysparm_limit=50

Operational Status Values:

Step 2: View Service Map CI Associations

Retrieve all CIs mapped to a specific business service to see its topology.

Using MCP:

Tool: SN-Query-Table
Parameters:
  table_name: svc_ci_assoc
  query: service=[service_sys_id]
  fields: sys_id,service,ci_id,ci_id.name,ci_id.sys_class_name,ci_id.operational_status,port,type,is_manual
  limit: 100

Using REST API:

GET /api/now/table/svc_ci_assoc?sysparm_query=service=[service_sys_id]&sysparm_fields=sys_id,service,ci_id,port,type,is_manual&sysparm_display_value=true&sysparm_limit=100

Step 3: Analyze Service Dependencies

Trace upstream and downstream dependencies for a business service.

Using MCP:

Tool: SN-Execute-Background-Script
Parameters:
  description: Map service dependency tree for a business service
  script: |
    var svcId = '[service_sys_id]';

    gs.info('=== SERVICE DEPENDENCY ANALYSIS ===');

    // Upstream dependencies (services this service depends on)
    gs.info('\n--- UPSTREAM DEPENDENCIES (Depends On) ---');
    var upstream = new GlideRecord('cmdb_rel_ci');
    upstream.addQuery('child', svcId);
    upstream.addQuery('type.name', 'Depends on::Used by');
    upstream.query();
    while (upstream.next()) {
      var parent = upstream.parent.getRefRecord();
      gs.info('Depends on: ' + parent.name + ' (' + parent.sys_class_name + ') | Status: ' + parent.operational_status.getDisplayValue());
    }

    // Downstream dependencies (services that depend on this)
    gs.info('\n--- DOWNSTREAM DEPENDENCIES (Used By) ---');
    var downstream = new GlideRecord('cmdb_rel_ci');
    downstream.addQuery('parent', svcId);
    downstream.addQuery('type.name', 'Depends on::Used by');
    downstream.query();
    while (downstream.next()) {
      var child = downstream.child.getRefRecord();
      gs.info('Used by: ' + child.name + ' (' + child.sys_class_name + ') | Status: ' + child.operational_status.getDisplayValue());
    }

    // CI count by class
    gs.info('\n--- CI COMPOSITION ---');
    var ga = new GlideAggregate('svc_ci_assoc');
    ga.addQuery('service', svcId);
    ga.addAggregate('COUNT');
    ga.groupBy('ci_id.sys_class_name');
    ga.query();
    while (ga.next()) {
      gs.info('Class: ' + ga.ci_id.sys_class_name + ' | Count: ' + ga.getAggregate('COUNT'));
    }

Using REST API:

# Upstream dependencies
GET /api/now/table/cmdb_rel_ci?sysparm_query=child=[service_sys_id]^type.name=Depends on::Used by&sysparm_fields=parent,type&sysparm_display_value=true

# Downstream dependencies
GET /api/now/table/cmdb_rel_ci?sysparm_query=parent=[service_sys_id]^type.name=Depends on::Used by&sysparm_fields=child,type&sysparm_display_value=true

Step 4: Review Discovery Patterns

Examine service mapping patterns to understand how CIs are discovered and mapped.

Using MCP:

Tool: SN-Query-Table
Parameters:
  table_name: sa_pattern
  query: active=true^ORDERBYname
  fields: sys_id,name,description,ci_type,status,pattern_type,last_run,run_count,success_count,failure_count
  limit: 50

Using REST API:

GET /api/now/table/sa_pattern?sysparm_query=active=true^ORDERBYname&sysparm_fields=sys_id,name,description,ci_type,status,pattern_type,last_run,run_count,success_count,failure_count&sysparm_display_value=true&sysparm_limit=50

Pattern Status Reference:

Step 5: Identify Mapping Gaps

Find CIs that are not associated with any business service.

Using MCP:

Tool: SN-Execute-Background-Script
Parameters:
  description: Find CIs with no service association (potential mapping gaps)
  script: |
    gs.info('=== SERVICE MAPPING GAP ANALYSIS ===');

    // Find servers not mapped to any service
    var ciClasses = ['cmdb_ci_server', 'cmdb_ci_app_server', 'cmdb_ci_db_instance', 'cmdb_ci_lb'];

    for (var i = 0; i < ciClasses.length; i++) {
      var className = ciClasses[i];
      var gr = new GlideRecord(className);
      gr.addQuery('operational_status', '1'); // Operational only
      gr.addQuery('install_status', '1');     // Installed
      gr.addJoinQuery('svc_ci_assoc', 'sys_id', 'ci_id', true); // LEFT JOIN - no association
      gr.setLimit(20);
      gr.query();

      if (gr.getRowCount() > 0) {
        gs.info('\n--- Unmapped ' + className + ' (showing up to 20) ---');
        while (gr.next()) {
          gs.info('CI: ' + gr.name + ' | IP: ' + gr.ip_address + ' | Location: ' + gr.location.getDisplayValue());
        }
      }
    }

    // Count total mapped vs unmapped
    gs.info('\n--- MAPPING COVERAGE SUMMARY ---');
    var totalCIs = new GlideAggregate('cmdb_ci');
    totalCIs.addQuery('install_status', '1');
    totalCIs.addAggregate('COUNT');
    totalCIs.query();
    totalCIs.next();
    var total = parseInt(totalCIs.getAggregate('COUNT'));

    var mappedCIs = new GlideAggregate('svc_ci_assoc');
    mappedCIs.addAggregate('COUNT', 'DISTINCT', 'ci_id');
    mappedCIs.query();
    mappedCIs.next();
    var mapped = parseInt(mappedCIs.getAggregate('COUNT', 'DISTINCT', 'ci_id'));

    gs.info('Total installed CIs: ' + total);
    gs.info('CIs mapped to services: ' + mapped);
    gs.info('Unmapped CIs: ' + (total - mapped));
    gs.info('Coverage: ' + Math.round((mapped / total) * 100) + '%');

Step 6: Validate Service Map Accuracy

Cross-reference service maps with active alerts to detect stale or incorrect mappings.

Using MCP:

Tool: SN-Execute-Background-Script
Parameters:
  description: Cross-reference service maps with alerts
  script: |
    gs.info('=== SERVICE MAP VALIDATION ===');

    var svc = new GlideRecord('cmdb_ci_service');
    svc.addQuery('active', true);
    svc.query();

    while (svc.next()) {
      // Check for alerts on CIs in this service
      var assoc = new GlideRecord('svc_ci_assoc');
      assoc.addQuery('service', svc.sys_id.toString());
      assoc.query();

      var alertCount = 0;
      var staleCIs = 0;

      while (assoc.next()) {
        var ciId = assoc.ci_id.toString();

        // Check for active alerts
        var alert = new GlideAggregate('em_alert');
        alert.addQuery('ci', ciId);
        alert.addQuery('state', '!=', 'Closed');
        alert.addAggregate('COUNT');
        alert.query();
        if (alert.next()) {
          alertCount += parseInt(alert.getAggregate('COUNT'));
        }

        // Check for stale CIs (not updated in 90 days)
        var ci = new GlideRecord('cmdb_ci');
        if (ci.get(ciId)) {
          var lastUpdate = new GlideDateTime(ci.sys_updated_on.toString());
          var cutoff = new GlideDateTime();
          cutoff.addDaysLocalTime(-90);
          if (lastUpdate.before(cutoff)) {
            staleCIs++;
          }
        }
      }

      if (alertCount > 0 || staleCIs > 0) {
        gs.info('Service: ' + svc.name + ' | Active Alerts: ' + alertCount + ' | Stale CIs: ' + staleCIs);
      }
    }

Step 7: Troubleshoot Failed Discovery Patterns

Investigate patterns that have failed or produced unexpected results.

Using MCP:

Tool: SN-Query-Table
Parameters:
  table_name: sa_pattern
  query: status=Failed^ORactive=true^failure_count>0
  fields: sys_id,name,ci_type,status,last_run,failure_count,success_count,error_message
  limit: 20

Using REST API:

GET /api/now/table/sa_pattern?sysparm_query=status=Failed^ORactive=true^failure_count>0&sysparm_fields=sys_id,name,ci_type,status,last_run,failure_count,success_count,error_message&sysparm_display_value=true&sysparm_limit=20

Tool Usage

MCP Tools Reference

REST API Reference

Best Practices

• Map Top-Down: Start with business services and map downward to infrastructure to ensure business context
• Validate After Discovery: Always review new pattern results before promoting to production service maps
• Monitor Coverage Metrics: Track the percentage of operational CIs mapped to services and set improvement targets
• Use Manual Entries Sparingly: Manual CI associations bypass discovery validation; prefer pattern-driven mapping
• Review Stale Mappings: Schedule quarterly reviews to remove decommissioned CIs from service maps
• Correlate with Change Management: Validate service maps after major changes to ensure topology accuracy

Troubleshooting

Pattern Fails with Credential Error

Cause: Discovery credentials are expired or lack permissions on the target host Solution: Verify credentials in Discovery Credentials module. Test SSH/WMI/SNMP connectivity from the MID Server.

CIs Missing from Service Map

Cause: Pattern does not cover the CI class or entry point is incorrect Solution: Review the pattern's entry point configuration. Check if the CI class has an applicable pattern. Verify network reachability from the MID Server.

Duplicate CIs in Service Map

Cause: Reconciliation rules not matching correctly, leading to duplicate CI creation Solution: Review IRE (Identification and Reconciliation Engine) rules for the affected CI class. Check discovery_source field for conflicting sources.

Service Map Shows Stale Topology

Cause: Discovery schedule not running or pattern disabled Solution: Verify the discovery schedule is active and running on the correct MID Server. Check sa_pattern.last_run to confirm execution.

Examples

Example 1: Full Service Topology Report

# 1. Get the business service
Tool: SN-Query-Table
Parameters:
  table_name: cmdb_ci_service
  query: name=Email Service
  fields: sys_id,name,operational_status,busines_criticality,owned_by
  limit: 1

# 2. Get all CIs in the service map
Tool: SN-Query-Table
Parameters:
  table_name: svc_ci_assoc
  query: service=[service_sys_id]
  fields: ci_id,ci_id.name,ci_id.sys_class_name,ci_id.operational_status,port,type
  limit: 200

# 3. Get dependency relationships
Tool: SN-Query-Table
Parameters:
  table_name: cmdb_rel_ci
  query: parent=[service_sys_id]^ORchild=[service_sys_id]
  fields: parent,child,type
  limit: 50

Example 2: Pre-Change Impact Assessment

# 1. Find all services affected by a CI undergoing change
Tool: SN-Query-Table
Parameters:
  table_name: svc_ci_assoc
  query: ci_id=[ci_sys_id]
  fields: service,service.name,service.busines_criticality,type
  limit: 20

# 2. For each affected service, get downstream consumers
Tool: SN-Query-Table
Parameters:
  table_name: cmdb_rel_ci
  query: parent=[service_sys_id]^type.name=Depends on::Used by
  fields: child,child.name,child.sys_class_name
  limit: 50

Example 3: Discovery Pattern Health Check

Tool: SN-Execute-Background-Script
Parameters:
  description: Summary of pattern health
  script: |
    var ga = new GlideAggregate('sa_pattern');
    ga.addQuery('active', true);
    ga.addAggregate('COUNT');
    ga.groupBy('status');
    ga.query();

    gs.info('=== PATTERN HEALTH SUMMARY ===');
    while (ga.next()) {
      gs.info('Status: ' + ga.status.getDisplayValue() + ' | Count: ' + ga.getAggregate('COUNT'));
    }

Related Skills

• itom/alert-analysis - Analyze alerts related to mapped services
• itom/observability-integration - Integrate external monitoring with service maps
• itom/health-log-analytics - Monitor health of mapped service components
• cmdb/relationship-mapping - CMDB relationship management
• cmdb/impact-analysis - Business impact analysis using service maps

References

• ServiceNow Service Mapping
• Discovery Patterns
• Service Mapping Best Practices