Quote from: coopex on December 02, 2019, 08:27:01 PM

Quote from: mechanikalk on December 02, 2019, 02:47:48 PM

Quote from: coopex on November 13, 2019, 10:51:51 PM

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.

Thanks for your response! I see now that miners are incentivized to run all of their nodes in the least latent way possible. However, miners might not physically be able to do so without moving their mining operation outside of the zone that they operate in, unless they want to pay a cloud provider to host it for them - which may not work if the cloud provider does not offer server hosting close enough or with proper precision to the geographic location of the zone. Perhaps a business could evolve to host servers in close proximity to every zone and move them around when necessary, kind of like high frequency trading does with the stock market, but even then you'd have the business be a centralizing factor.

In any case, my question is more general. Do you consider it an issue if some of the nodes in a zone are more latent than others? Are there bandwidth concerns with users or miners who run latent nodes? What if I just have a really shitty internet connection - could I be causing bandwidth issues for the network, or am I just causing issues for myself?

Thank you for your responses!

That is a pretty insightful question. However, the answer is pretty simple. With all distributed networks from things like Napster to Bitcoin you always have a seed and a leech problem. In the example of Napster it is driven by storage space more than bandwidth. In the context of Bitcoin it is driven by bandwidth more than storage. Therefore, if you are a Bitcoin node that has low bandwidth you are slowing the overall network down (leech), whereas if you have high bandwidth you are speeding it up (seed). BlockReduce is not different from Bitcoin in this regard. However, BlockReduce rewards mining in the zone chains creating an economic incentive for participants who are mining to optimize for latency.