A Citrix Administrator executed the following command in the Global Server Load Balancing (GSLB) environment:set...

According to the Citrix documentation1, the triggerMonitor parameter specifies the conditions under which the service monitor is invoked. The possible values are:

ALWAYS: The service monitor is always invoked.

MEPDOWN: The service monitor is invoked only when Metric Exchange Protocol (MEP) has marked the service as DOWN for any reason.

MEPSUSPECT: The service monitor is invoked only when MEP has marked the service as SUSPECT.

NONE: The service monitor is never invoked.

Therefore, the command set gslb site SiteB –triggerMonitor MEPDOWN will set the triggerMonitor value to MEPDOWN for SiteB, which means the service monitor is invoked only when MEP has marked the service as DOWN for any reason.

1: https://docs.citrix.com/en-us/citrix-adc/13/gslb/configure-gslb-site.html