Load balancer: Citrix Netscaler

Discovery of Citrix Netscaler load balancers is performed by SNMP.

Requirements

Important: Discovery treats hardware load balancers as network devices and attempts to discover them primarily using SNMP. If a load balancer in your system running on a Linux host has SNMP and SSH ports open, Discovery might classify it based on the SSH port, which has classification priority over SNMP. To ensure that Discovery properly classifies your hardware load balancers, create a Discovery behavior for load balancers that includes SNMP but not SSH. Software load balancers are treated as applications.
Consider the following requirements for discovering Citrix Netscaler load balancers:
  • The Citrix Netscaler device is installed and running on the network.
  • The Citrix Netscaler probes require SNMP credentials to run commands.

Probes

The SNMP - Classify probe detects Citrix Netscaler load balancers with the following SNMP MIB: NS-ROOT-MIB

The following probes are triggered after classification:
Table 1. Citrix Netscaler probes
Probe Description
SNMP - Netscaler – Identity MultiProbe that queries for the serial number and other identifying information.
SNMP - Netscaler – Identity - Serial Retrieves the Netscaler chassis serial number, which is globally unique for this vendor.
SNMP - Netscaler - System Collects information on the Netscaler, including pools, services, and VLANs.
The Citrix Netscaler load balancer model represents a generic load balancer and its components. The abstract class is stored in the Load Balancer [cmdb_ci_lb] table. The implementation class, extended from Load Balancer, is stored in the Citrix Netscalers [cmdb_ci_lb_netscaler] table.
Note: See Load balancer fields and probes for a list of the fields that are populated by these probes.
Note:

Discovery does not gather the load balancer interface information that is necessary to map the network path in Service Mapping. Service maps might not appear correct.

CI relationships

A Citrix Netscaler discovery creates relationships between the application and the load balance service as well as groups and group members if the application CI exists. However, if the application CI was not discovered, the SNMP - Netscaler - System sensor will map between the computer and the load balance service instead.

In this example from the ServiceNow dependency view (BSM map), a Netscaler load balancer is represented by these elements:
  • netscaler: Actual Netscaler load balancer CI created by Discovery.
  • VIP1: Virtual IP address that is the entry point for all business services attempting to contact the load balancer.
  • New_Service_Group: Group containing the web server pool members.
Figure 1. Sample Citrix Netscaler load balancer configuration