Restoring Last State after reboot or power failure

Hi Friends, I am a newbie in Cayenne and I have been trying some projects using Cayenne. I am facing a problem to restore the last state of the outputs after power failure. I had tried even by using SyncAll() but nothing have been happened. I understood that no need to use SyncAll() as it will be handling by MQTT broker. Can somebody help me to resolve the problem?.
Thanks & Regards in advance,

Cayenne MQTT broker has no retain flag implemented hence the last state is not stored. You can EEPROM to store the state on the device itselg.

Hi Mr.Shramik,
Thank you very much.I will try using EEPROM.