I want to update the version of Cardano-cli in my node using the following guide. I wonder what are the consequence of making my node unavailable (stopping the processes, restarting the node) during the update process?
Networking between cardano nodes follows a pull model. When the block producer is down, it cannot mint blocks that it is scheduled for. The leaderlog would tell you when that is supposed to happen. When your relay is down, it cannot pull the block(s) minted by your block producer.
I personally do maintenance, when I know that the block producer is going to be idle for a while.
How do you check if the block producer is idle for a while?
Also what happens if producer or relay cant process blocks that they are scheduled for? e.g., only won’t receive reward for that epoch etc?
You run the leaderlog schedule.
No block, no reward - otherwise no consequence i.e. there is no “slashing” in Cardano.