Hi there! I was looking through some old research papers about merge-mining and came upon this thread. I'm very interested in your proposal as it seems like a great way to shard state without losing security via merge mining! I have a question for you though: If miners have to verify all the state that passes up to Prime, they have to run a full node so that they have the state of all the blockchains to properly verify everything. They are incentivized to do this so that they don't mine invalid blocks, but in doing so they might put a strain on the network because their zone and region nodes are not necessarily in the same geographic region as the rest of the zone and region nodes. (Of course, the zone that the miner is located in will be optimal, but I am talking about the rest of the zones and regions necessary for running a full state node).
For example, for n zones, n/2 regions, and m miners running a full state node, we have m - 1 latent nodes in each zone (or n*(m-1) latent zone nodes total) and m - 1 latent nodes in each region (or (n/2)*(m-1) latent region nodes total). Do you consider this an issue for network latency? Is there perhaps some way or incentive for a miner to run a full node and also run each sub-node (zone and region) in the proper geographic location? This might be physically difficult without the use of some cloud provider like AWS.
Looking forward to hearing more! Thanks.
Coopex, great question! Sorry, it has taken me a bit to get back to you. The miner is incentivized to hold zone state which they are not mining because it reduces the risk they will include a zone block in a region block which eventually gets rolled back in the zone. If they were to wait or delay including zone blocks in the region blocks, they could also achieve greater certainty, however they would get lower rewards. Running the alternate zone state allows them to have greater certainty about a zone block faster. Doing so with a node which is appropriately placed in the network topology will decrease that nodes latency and further decrease risk. Therefore, miners will be incentivized to keep state and do so in a network optimal way. I would absolutely expect that a person running full state would do so using something like AWS to allow optimization of the geographic placement of nodes.