NetScalerGroupHealthMonitor

This monitor is designed for Citrix® NetScaler® loadbalancing checks. It checks if more than x percent of the servers assigned to a specific group on a loadbalanced service are active. The required data is gathered via SNMP from the NetScaler®. The status of the servers is determined by the NetScaler®. The provided service it self is not part of the check. The basis of this monitor is the SnmpMonitorStrategy. A valid SNMP configuration in OpenNMS HORIZON for the NetScaler® is required.

A NetScaler® can manage several groups of servers per application. This monitor just covers one group at a time. If there are multiple groups to check, define one monitor per group.
This monitor is not checking the loadbalanced service it self.
Monitor facts

Class Name

org.opennms.netmgt.poller.monitors.NetScalerGroupHealthMonitor

Remote Enabled

false

Configuration and Usage
Table 1. Monitor specific parameters for the NetScalerGroupHealthMonitor
Parameter Description Required Default value

group-name

The name of the server group to check

required

-

group-health

The percentage of active servers vs total server of the group as an integer

optional

60

Examples

The following example checks a server group called central_webfront_http. If at least 70% of the servers are active, the service is up. If less then 70% of the servers are active the service is down. A configuration like the following can be used for the example in the poller-configuration.xml.

<service name="NetScaler_Health" interval="300000" user-defined="false" status="on">
   <parameter key="group-name" value="central_webfront_http" />
   <parameter key="group-health" value="70" />
</service>

<monitor service="NetScaler_Health" class-name="org.opennms.netmgt.poller.monitors.NetScalerGroupHealthMonitor” />
Details about the used SNMP checks

The monitor checks the status of the server group based on the NS-ROOT-MIB using the svcGrpMemberState. svcGrpMemberState is part of the serviceGroupMemberTable. The serviceGroupMemberTable is indexed by svcGrpMemberGroupName and svcGrpMemberName. A initial lookup for the group-name is performed. Based on the lookup the serviceGroupMemberTable is walked with the numeric representation of the server group. The monitor interprets just the server status code 7-up as active server. Other status codes like 2-unknown or 3-busy are counted for total amount of servers.