What is the purpose of having a local only shadow in AWS IoT greengrass?

Question

AWS IoT greengrass works over a local network. This means there is no problem/need for an internet connection. So why is local only shadow concept provided in AWS IoT greengrass?

It makes sense to use local shadow when sync'd with cloud so that when IoT core tries to send msg to greengrass device when there is no internet connectivity then the msg is not lost, and instead the msg is sent to IoT core shadow and then the greengrass device will get the msg when the connectivity is available.

But other than this what is the reason for a local only greengrass shadow?

Answer 1

I am guessing here and I want to be corrected if wrong. The purpose of local only shadow - suppose I am a mining client and have no need for (or cannot have) internet connectivity - I am in some remote part of the world. But I have a lot of local systems/devices on-prem performing state change on my device - I want to sequence the calls for state change and not loose them if my device needs to reboot. In this context I would need a local shadow.