cmdb-patterns

CMDB Patterns for ServiceNow

The Configuration Management Database (CMDB) is the foundation of ServiceNow ITSM, tracking all Configuration Items (CIs) and their relationships.

CMDB Architecture CI Class Hierarchy cmdb (Base) └── cmdb_ci (Configuration Item) ├── cmdb_ci_computer │ ├── cmdb_ci_server │ │ ├── cmdb_ci_linux_server │ │ ├── cmdb_ci_win_server │ │ └── cmdb_ci_unix_server │ └── cmdb_ci_pc_hardware ├── cmdb_ci_service │ ├── cmdb_ci_service_auto │ └── cmdb_ci_service_discovered ├── cmdb_ci_appl │ ├── cmdb_ci_app_server │ └── cmdb_ci_db_instance └── cmdb_ci_network_gear ├── cmdb_ci_netgear └── cmdb_ci_lb

Key CI Tables Table Purpose Key Fields cmdb_ci Base CI table name, sys_class_name, operational_status cmdb_ci_server Servers ip_address, os, cpu_count, ram cmdb_ci_service Business Services service_classification, busines_criticality cmdb_ci_appl Applications version, install_directory cmdb_rel_ci CI Relationships parent, child, type Creating Configuration Items Basic CI Creation (ES5) // Create a new server CI var ci = new GlideRecord('cmdb_ci_server'); ci.initialize(); ci.setValue('name', 'PROD-WEB-001'); ci.setValue('ip_address', '10.0.1.100'); ci.setValue('os', 'Linux Red Hat'); ci.setValue('os_version', '8.5'); ci.setValue('cpu_count', 8); ci.setValue('ram', 32768); ci.setValue('operational_status', 1); // Operational ci.setValue('install_status', 1); // Installed ci.setValue('used_for', 'Production'); ci.setValue('owned_by', 'sys_id_of_owner'); ci.setValue('support_group', 'sys_id_of_group'); var sysId = ci.insert();

CI with Discovery Source // CI from Discovery var ci = new GlideRecord('cmdb_ci_linux_server'); ci.initialize(); ci.setValue('name', 'discovered-server-001'); ci.setValue('discovery_source', 'ServiceNow'); ci.setValue('first_discovered', new GlideDateTime()); ci.setValue('last_discovered', new GlideDateTime()); ci.setValue('ip_address', '10.0.2.50');

// Set classification ci.setValue('classification', 'Production'); ci.setValue('environment', 'Production');

ci.insert();

CI Relationships Relationship Types Type Parent → Child Example Runs on::Runs App → Server ERP runs on PROD-DB-01 Depends on::Used by Service → App HR Service depends on SAP Contains::Contained by Cluster → Server Cluster contains Node1 Hosted on::Hosts VM → Hypervisor VM01 hosted on ESX01 Members::Member of CI → Group Server member of Pool Creating Relationships (ES5) // Create relationship between CIs function createCIRelationship(parentSysId, childSysId, relationType) { // Find relationship type var relType = new GlideRecord('cmdb_rel_type'); relType.addQuery('name', relationType); relType.query();

if (!relType.next()) {
    gs.error('Relationship type not found: ' + relationType);
    return null;
}

// Check if relationship already exists
var existing = new GlideRecord('cmdb_rel_ci');
existing.addQuery('parent', parentSysId);
existing.addQuery('child', childSysId);
existing.addQuery('type', relType.getUniqueValue());
existing.query();

if (existing.next()) {
    gs.info('Relationship already exists');
    return existing.getUniqueValue();
}

// Create new relationship
var rel = new GlideRecord('cmdb_rel_ci');
rel.initialize();
rel.setValue('parent', parentSysId);
rel.setValue('child', childSysId);
rel.setValue('type', relType.getUniqueValue());
return rel.insert();

}

// Usage createCIRelationship(appSysId, serverSysId, 'Runs on::Runs');

Querying Relationships // Find all servers an application runs on function getAppServers(appSysId) { var servers = [];

var rel = new GlideRecord('cmdb_rel_ci');
rel.addQuery('parent', appSysId);
rel.addQuery('type.name', 'Runs on::Runs');
rel.query();

while (rel.next()) {
    var server = rel.child.getRefRecord();
    servers.push({
        sys_id: server.getUniqueValue(),
        name: server.getValue('name'),
        ip_address: server.getValue('ip_address')
    });
}

return servers;

}

// Find all dependencies of a service function getServiceDependencies(serviceSysId) { var deps = [];

var rel = new GlideRecord('cmdb_rel_ci');
rel.addQuery('parent', serviceSysId);
rel.addQuery('type.name', 'Depends on::Used by');
rel.query();

while (rel.next()) {
    deps.push({
        sys_id: rel.child.getUniqueValue(),
        name: rel.child.getDisplayValue(),
        class: rel.child.sys_class_name.toString()
    });
}

return deps;

}

Impact Analysis Upstream/Downstream Analysis // Get all CIs affected by a CI outage (downstream impact) function getDownstreamImpact(ciSysId, depth) { if (typeof depth === 'undefined') depth = 3;

var impacted = [];
var processed = {};

function traverse(sysId, currentDepth) {
    if (currentDepth > depth || processed[sysId]) return;
    processed[sysId] = true;

    var rel = new GlideRecord('cmdb_rel_ci');
    rel.addQuery('child', sysId);
    rel.query();

    while (rel.next()) {
        var parentId = rel.parent.toString();
        if (!processed[parentId]) {
            impacted.push({
                sys_id: parentId,
                name: rel.parent.getDisplayValue(),
                depth: currentDepth
            });
            traverse(parentId, currentDepth + 1);
        }
    }
}

traverse(ciSysId, 1);
return impacted;

}

// Get all CIs this CI depends on (upstream dependencies) function getUpstreamDependencies(ciSysId, depth) { if (typeof depth === 'undefined') depth = 3;

var dependencies = [];
var processed = {};

function traverse(sysId, currentDepth) {
    if (currentDepth > depth || processed[sysId]) return;
    processed[sysId] = true;

    var rel = new GlideRecord('cmdb_rel_ci');
    rel.addQuery('parent', sysId);
    rel.query();

    while (rel.next()) {
        var childId = rel.child.toString();
        if (!processed[childId]) {
            dependencies.push({
                sys_id: childId,
                name: rel.child.getDisplayValue(),
                depth: currentDepth
            });
            traverse(childId, currentDepth + 1);
        }
    }
}

traverse(ciSysId, 1);
return dependencies;

}

Business Service Impact // Find all business services impacted by a CI function getImpactedServices(ciSysId) { var services = []; var processed = {};

function findServices(sysId) {
    if (processed[sysId]) return;
    processed[sysId] = true;

    // Check if this CI is a service
    var ci = new GlideRecord('cmdb_ci');
    if (ci.get(sysId)) {
        if (ci.sys_class_name.toString().indexOf('cmdb_ci_service') === 0) {
            services.push({
                sys_id: sysId,
                name: ci.getValue('name'),
                criticality: ci.getValue('busines_criticality')
            });
        }
    }

    // Traverse upstream
    var rel = new GlideRecord('cmdb_rel_ci');
    rel.addQuery('child', sysId);
    rel.query();

    while (rel.next()) {
        findServices(rel.parent.toString());
    }
}

findServices(ciSysId);
return services;

}

CMDB Health & Data Quality Orphan CI Detection // Find CIs without relationships function findOrphanCIs(ciClass) { var orphans = [];

var ci = new GlideRecord(ciClass || 'cmdb_ci');
ci.addQuery('operational_status', 1);  // Operational only
ci.query();

while (ci.next()) {
    var sysId = ci.getUniqueValue();

    // Check for any relationships
    var rel = new GlideRecord('cmdb_rel_ci');
    rel.addQuery('parent', sysId)
       .addOrCondition('child', sysId);
    rel.setLimit(1);
    rel.query();

    if (!rel.hasNext()) {
        orphans.push({
            sys_id: sysId,
            name: ci.getValue('name'),
            class: ci.getValue('sys_class_name')
        });
    }
}

return orphans;

}

Stale CI Detection // Find CIs not updated by discovery function findStaleCIs(daysOld) { if (typeof daysOld === 'undefined') daysOld = 30;

var stale = [];
var cutoff = new GlideDateTime();
cutoff.addDaysLocalTime(-daysOld);

var ci = new GlideRecord('cmdb_ci');
ci.addQuery('operational_status', 1);
ci.addQuery('last_discovered', '<', cutoff);
ci.addNotNullQuery('last_discovered');
ci.query();

while (ci.next()) {
    stale.push({
        sys_id: ci.getUniqueValue(),
        name: ci.getValue('name'),
        last_discovered: ci.getValue('last_discovered')
    });
}

return stale;

}

MCP Tool Integration Available CMDB Tools Tool Purpose snow_create_ci Create new CI with proper class snow_cmdb_search Search CIs with filters snow_create_ci_relationship Create CI relationships snow_impact_analysis Analyze CI impact snow_get_ci_details Get full CI information snow_run_discovery Trigger discovery Example Workflow // 1. Search for existing CI await snow_cmdb_search({ ci_class: 'cmdb_ci_server', query: 'name=PROD-WEB-001', include_relationships: true });

// 2. Create new CI if not found await snow_create_ci({ ci_class: 'cmdb_ci_linux_server', name: 'PROD-WEB-002', ip_address: '10.0.1.101', operational_status: 1 });

// 3. Create relationship await snow_create_ci_relationship({ parent: appSysId, child: serverSysId, type: 'Runs on::Runs' });

// 4. Impact analysis await snow_impact_analysis({ ci_sys_id: serverSysId, direction: 'downstream', depth: 3 });

Best Practices Use Correct CI Class - Always use most specific class (cmdb_ci_linux_server, not cmdb_ci) Maintain Relationships - CIs without relationships have limited value Discovery Alignment - Align manual CIs with discovery patterns Operational Status - Keep status current (Operational, Retired, etc.) Unique Identifiers - Use serial_number, asset_tag for uniqueness Service Mapping - Connect CIs to business services Regular Cleanup - Archive retired CIs, remove orphans