Load balancer fields and probes

  • Release version: Zurich
  • Updated July 31, 2025
  • 4 minutes to read
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    Summary of Load balancer fields and probes

    This content explains how ServiceNow Discovery collects and stores load balancer information using probes and sensors during discovery. It focuses on the data fields discovered for various load balancer types and their corresponding database tables. Note that pattern-based discovery for specific load balancers like F5 Big-IP is documented separately.

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    By default, Discovery uses the load balancer's discovered IP address (usually a management IP) for the configuration item (CI) record. Customers can configure Discovery to use the IP address of the load balancer’s network interface card (NIC) instead, via IP address selection properties.

    Load Balancer Tables and Key Fields

    Discovery maps load balancer data into multiple CMDB tables, each representing different load balancer types or components. Each table includes specific fields populated by relevant probes:

    • Citrix Netscalers [cmdbcilbnetscaler]: Fields like serial number, asset tag, and model ID gathered via SNMP probes.
    • Cisco GSS [cmdbcilbciscogss]: Includes serial number, model ID, IP address, and manufacturer information from Cisco GSS-specific probes.
    • Cisco CSS [cmdbcilbciscocss]: Contains serial number, model ID, IP address, and manufacturer fields gathered via SNMP.
    • F5 BIG-IP [cmdbcilbbigip]: Captures active modules, asset tag, model ID, failover mode and peer, and serial number. Some fields require form customization to be visible.
    • Load Balancer [cmdbcilb]: General fields such as operational status and name, collected from multiple probes including Apache and SNMP.
    • Load Balancer Application [cmdbcilbappl]: Includes configuration file, name, IP address, last discovery date, and version information from Apache, HAProxy, and Nginx probes.
    • Load Balancer Interface [cmdbcilbinterface]: Fields like status, load balancer reference, and name, with some requiring form customization.
    • Load Balancer Pool [cmdbcilbpool]: Contains load balancing method, load balancer reference, discovery date, and name fields.
    • Load Balancer Pool Member [cmdbcilbpoolmember]: Stores fully qualified domain names, IP addresses, load balancer reference, discovery date, associated pool, service port, and name.
    • Load Balancer Service [cmdbcilbservice]: Includes input URL, IP address, last port, load balancer reference, discovery date, and service port.
    • Load Balancer VLAN [cmdbcilbvlan]: Captures load balancer reference, name, and tag information.

    Fields marked as not visible by default require form customization to be displayed in the user interface.

    Apache Web Server Data

    Discovery also collects information on Apache web server load balancing modules using SSH-based probes. For detailed data on Apache modjk and modproxy modules, refer to the Apache web server discovery documentation.

    Practical Implications for ServiceNow Customers

    • Understanding which probes populate which fields helps customers verify and customize load balancer data in their CMDB effectively.
    • Customers can tailor forms to display important but hidden fields to better manage load balancer CI data.
    • Configuring IP address selection allows aligning discovered IPs with organizational preferences for management or NIC addresses.
    • Recognizing the distinction between probe-based and pattern-based discovery ensures correct application of discovery methods for different load balancer types.

    Discovery stores load balancer information in several tables.

    The information in this topic pertains to discovery with probes and sensors only. If you are using patterns, such as to discover F5 Big-IP load balancers, see the relevant topic for that type of load balancer.

    Note:
    By default, the system uses the discovered IP address of a load balancer for the CI record. This can be the management IP created for the device that is used in the Discovery schedule. For instructions on how to force Discovery to use the IP address of the load balancer's NIC rather than that of a management IP, see IP address selection properties.
    Table 1. Fields on the Citrix Netscalers [cmdb_ci_lb_netscaler] table
    Field label and name Probes that gather data
    Serial Number [serial_number] SNMP - Netscaler - Identity - Serial
    Asset tag [asset_tag] SNMP - Netscaler - Identity
    Model ID [model_id] SNMP - Netscaler - Identity
    Table 2. Fields on the Cisco GSS [cmdb_ci_lb_cisco_gss] table
    Field label and name Probes that gather data
    Serial Number [serial_number] Cisco GSS - Serial Number
    Model ID [model_id] Cisco GSS - Identity
    IP Address [ip_address] Cisco GSS - Network
    Manufacturer [manufacturer] Cisco GSS - Identity
    Table 3. Fields on the Cisco CSS [cmdb_ci_lb_cisco_css] table
    Field label and name Probes that gather data
    Serial Number [serial_number] SNMP - Load Balancer – Identity
    Model ID [model_id]
    IP Address [ip_address]
    Manufacturer [manufacturer]
    Table 4. Fields on the F5 BIG-IP [cmdb_ci_lb_bigip] table
    Field label and name Probes that gather data
    Active modules [active_modules]* SNMP - F5 BIG-IP - System
    Asset tag [asset_tag]
    Model ID [model_id]
    Failover mode [failover_mode]*
    Failover peer [failover_peer]*
    Serial Number [serial_number] Cisco GSS - Serial Number
    *not visible on the form by default. Customize the form to add this field.
    Table 5. Fields on the Load Balancer [cmdb_ci_lb] table
    Field label and name Probes that gather data
    Operational status [operational_status]
    • Apache - Get JK Module
    • Apache - Get Proxy Module
    • HAProxy - Get Configuration
    • SNMP - F5 BIG-IP - System
    • SNMP - Netscaler - System
    • SNMP - Load Balancer - Identity
    Name [name]
    Table 6. Fields on the Load Balancer Application [cmdb_ci_lb_appl] table
    Field label and name Probes that gather data
    Configuration file [config_file]* Nginx - Get Configuration
    Name [name]
    • Apache - Get JK Module
    • Apache - Get Proxy Module
    • HAProxy - Get Configuration
    • Nginx - Get Configuration
    IP Address [ip_address]*
    Most recent discovery [last_discovered]*
    Version [version]
    • Apache - Version
    • HAProxy - Version
    • Nginx - Version
    Table 7. Fields on the Load Balancer Interface [cmdb_ci_lb_interface] table
    Field label and name Probes that gather data
    Status [install_status]*
    • Apache - Get JK Module
    • Apache - Get Proxy Module
    • HAProxy - Get Configuration
    • SNMP - F5 BIG-IP - System
    • SNMP - Netscaler - System
    Load Balancer [load_balancer]
    Name [name]
    *not visible on the form by default. Customize the form to add this field.
    Table 8. Fields on the Load Balancer Pool [cmdb_ci_lb_pool] table
    Field label and name Probes that gather data
    Load Balancing Method [load_balance_method]
    • Apache - Get JK Module
    • Apache - Get Proxy Module
    • HAProxy - Get Configuration
    • SNMP - F5 BIG-IP - System
    • SNMP - Netscaler - System
    Load Balancer [load_balancer]
    Most recent discovery [last_discovered]*
    Name [name]
    *not visible on the form by default. Customize the form to add this field.
    Table 9. Fields for Load Balancer Pool Member [cmdb_ci_lb_pool_member] data
    Field label and name Probes that gather data
    Fully qualified domain name [fqdn]*
    • HAProxy - Get Configuration
    • Nginx - Get Configuration
    • SNMP - F5 BIG-IP - System
    • SNMP - Netscaler - System
    IP Address [ip_address]
    • Apache - Get JK Module
    • Apache - Get Proxy Module
    • HAProxy - Get Configuration
    • Nginx- Get Configuration
    • SNMP - F5 BIG-IP - System
    • SNMP - Netscaler - System
    Load balancer [load_balancer]
    Most recent discovery [last_discovery]*
    Name [name]
    Pool [pool]*
    Service Port [service_port]
    *not visible on the form by default. Customize the form to add this field.
    Table 10. Fields for Load Balancer Service [cmdb_ci_lb_service] data
    Field label and name Probes that gather data
    Input URL [input_url]
    • Apache - Get JK Module
    • Apache - Get Proxy Module
    • Nginx - Get Configuration
    IP Address [ip_address]
    • Apache - Get JK Module
    • Apache - Get Proxy Module
    • Cisco GSS - Identity
    • HAProxy - Get Configuration
    • Nginx - Get Configuration
    • SNMP - F5 BIG-IP - System
    • SNMP - Netscaler - System
    Last port [last_port]* HAProxy - Get Configuration
    Load Balancer [load_balancer]
    • Apache - Get JK Module
    • Apache - Get Proxy Module
    • Cisco GSS - Identity
    • HAProxy - Get Configuration
    • Nginx - Get Configuration
    • SNMP - F5 BIG-IP - System
    • SNMP - Netscaler - System
    Most recent discovery [last_discovery]*
    Service Port [service_port]*
    *not visible on the form by default. Customize the form to add this field.
    Table 11. Fields for Load Balancer VLAN [cmdb_ci_lb_vlan] data
    Field label and name Probes that gather data
    Load Balancer [load_balancer]
    • Apache - Get JK Module
    • Apache - Get Proxy Module
    • HAProxy - Get Configuration
    • Nginx - Get Configuration
    • SNMP - F5 BIG-IP - System
    • SNMP - Netscaler - System
    Name [name]
    Tag [tag]
    • SNMP - F5 BIG-IP - System
    • SNMP - Netscaler - System

    Apache web server data

    Discovery also collects data on Apache web serer load balancing modules using SSH. See Apache mod_jk and mod_proxy discovery for more information on probes for Apache web server data. For information on the tables, fields, and data sources that discovery populates for Apache web servers, see Apache web server discovery.