Scenario: A Citrix Administrator needs to configure persistence on a global server load balancing (GSLB) vServer to which a service is bound. Service…

The scenario describes a graceful shutdown of a service. The Wait time parameter is specifically designed for this purpose. When an administrator disables a service and specifies a wait time, the Citrix ADC appliance transitions the service to an "OUT OF SERVICE" state. In this state, it stops accepting new connections but continues to serve existing client connections, thereby honoring persistence. After the configured wait time expires, the service is fully disabled, and any remaining connections are terminated. This process ensures a non-disruptive shutdown for active users.

A. Persistence threshold: This parameter is used within a persistence group to define a threshold that, when met, triggers the use of a backup virtual server. It is not related to disabling a service.
B. Persistence time-Out: This is a global or vServer-level setting that defines the inactivity period after which a persistence session expires. It is not configured during the act of disabling a service.
D. Request threshold: This is not a standard parameter for the service disablement process. Thresholds like maxReq limit the number of requests a service can handle but do not control its shutdown behavior.

1. Citrix ADC 13.1 Product Documentation: In the section on configuring services

the process for a graceful shutdown is detailed. It states

"To specify the time that the appliance waits before it hard-disables the service

you use the Wait Time parameter. When the graceful shutdown is initiated

the service is marked as OUT OF SERVICE

and it does not accept new connections. However

it continues to serve existing connections until the wait time expires."

Source: Citrix ADC 13.1 Documentation

"Traffic Management > Load Balancing > Services > Enable or disable a service".

2. Citrix ADC 13.1 Command Reference: The disable service command includes the -delay parameter

which corresponds to the "Wait Time" in the GUI. The documentation for this command explains that the delay specifies the number of seconds to wait before the service connections are terminated after the graceful shutdown is initiated.

Source: Citrix ADC 13.1 Command Reference

disable service command syntax and parameter descriptions.