Create following registry keys on controllers :
Registry Path : HKLMSoftwareCitrixDesktopServerSiteServices
Name : MaxShutdownTimeSecs
Type : REG_DWORD
Data : 1800 (Decimal)
Default : 20 (sec)
Registry Path : HKLMSOFTWARECitrixDesktopServerRebootSchedule
Name : MaxShutdownDelayMin
Type : REG_DWORD
Data : 60 (Decimal)
Default : 10
Info: Minutes Minimum=1 Maximum=60
Registry Path : HKLMSOFTWARECitrixDesktopServerRebootSchedule
Name : ShutdownTimeoutRecovery
Type : REG_DWORD
Data : 1 (Decimal)