Scenario: A Citrix Administrator needs to configure persistence on a Global Server Load Balancing (GSLB) virtual server to which a service is bound…

The scenario describes the process of a "graceful shutdown" for a service on a Citrix ADC. When a service is disabled gracefully, it stops accepting new connections but continues to handle traffic for existing persistent sessions. The Wait Time (referred to as the delay parameter in the command-line interface) is a specific value configured at the time of disabling the service. This parameter defines the duration, in seconds, that the ADC will wait before forcibly terminating any remaining active connections to that service. This allows existing sessions to complete naturally while preventing the service from accepting entirely new client sessions.

A. Request Threshold: This is a monitoring parameter used to determine the health of a service based on request rates, not a setting for disabling a service.
B. Persistence Time-Out: This parameter defines the inactivity period after which a persistence session expires. It is a general setting for the virtual server, not a parameter configured during the service disable action.
C. Persistence Threshold: This is not a valid parameter in the context of disabling a Citrix ADC service.

1. Citrix ADC 13.1 Product Documentation, "Disable a service": The documentation for the disable service command explicitly details the parameters for a graceful shutdown.

Section: Command reference > disable service

Content: The -graceful YES option is used to "Wait for all existing connections to the service to close before disabling the service." The -delay parameter, which corresponds to the "Wait Time," is defined as the "Time, in seconds, after which all the active connections to the service will be terminated." This directly matches the requirements described in the scenario.

2. Citrix ADC 13.1 Product Documentation, "Graceful shutdown of services": This section explains the concept and its application.

Section: Load Balancing > Services > Graceful shutdown of services

Content: "When you gracefully shut down a service, the Citrix ADC appliance stops accepting new connections to the service... If you specify a timeout, the appliance terminates any connections that are still active when the timeout expires." This confirms that a specific timeout (Wait Time/delay) is configured as part of the graceful shutdown process.