Published on: 2016-01-29T19:11:52+00:00
In a discussion on the Bitcoin-dev mailing list, Jannes Faber raised concerns about the impact of a non-contentious hard fork on the remaining 1% chain. Peter Todd responded by discussing the risks of hard forks and suggested that activation thresholds for hard forks should be above 99%, measured over a multi-week timespan. He also mentioned that high activation thresholds could be soft-forked down later and that delaying the fork by two or three months if stragglers won't upgrade would not cause much harm. Todd emphasized that hard forks should not be controversial for social/political reasons, except in rare cases like security issues. He referred to his previous post on the technical risks of non-controversial forks.The email thread from January 29, 2016, focused on the impact of a fork during the difficulty period. The BIP9 optimization checks for new activations only during difficulty retargettings. However, it is not assumed that all implementations will follow this approach. BIP99 proposes a 95% activation threshold for uncontroversial rule changes and no miner signaling for controversial hard forks. The proposal includes simple fixes like the timewarp fix forward-ported from Freicoin 0.8. There has been limited interest in expanding the list of easy-to-implement changes. BIP99 has not faced opposition as a hardfork proposal, but it is not currently a priority. It may be classified as a BIP without code, and the hardfork proposal itself should have been separate.In another bitcoin-dev mailing list discussion, Jannes Faber expressed concerns about the effects of a hard or soft fork on non-upgraded clients, specifically regarding the 2016 blocks recalibration window. Gavin Andresen responded by stating that the timing of the fork within the difficulty period does not matter significantly. If the fork happens in the middle, the lower-power fork's difficulty will adjust slightly quicker. However, Andresen acknowledged that this scenario is unrealistic, as minority forks with single-digit percentages of hash power would cause significant delays and difficulty adjustments lasting months before normal block times are resumed. He referred to his blog post on minority branches, explaining why miners have little incentive to mine on a minority fork.The writer of the email seeks clarification on the effects of hard or soft forks, particularly related to the timing of implementing new rules and their impact on non-upgraded clients. They present four options for when to apply new rules, all related to the 2016 blocks recalibration window. The writer discusses the potential consequences of each option, particularly in the case of a contentious 75-25 hard fork, where option 4 would be best for the conservative chain. They also consider scenarios where it may be beneficial for the remaining 1% chain to never reach 2016 blocks again. The writer questions whether all possible scenarios have been considered and suggests that defining the best choice should be mandatory for any hard fork proposal, possibly through BIP9. Additionally, the writer acknowledges that the first few blocks mined after implementing new rules may not immediately adhere to the new guidelines.
Updated on: 2023-08-01T17:40:54.328255+00:00