Reevaluating Parent Grinding Faults

[ZenGround0]

It's recently been raised that some storage providers are running into situations where they naturally create parent grinding faults when mining as normal. This causes storage providers to miss blocks. Details here.

There is a tradeoff here between security and fairness. In particular SPs with worse network connectivity will be more likely to miss the full tipset before mining a block leading to the above situation. It's not obvious to me that the current parent grinding consensus fault type is the right tradeoff.

So far @llifezou has reported this situation. It would be good to learn if others have this problem.

Note that parent grinding faults only apply in the case where a miner wins two blocks in a row, so in normal operation this is a relatively rare event. Even if we agree that these faults do more harm than good it's possibly not worth the effort to do anything about it.

[steven004]

Agreed. We do not need to do anything about it, not only because this is relatively rare, but we do not really know if a storage provider is out of sync, or intensionally just choose some blocks as parents to mine. That is, if we loose the check, a storage provider could attack the network by forking the chain via mining on selected blocks.