A discussion of rolling out BIP 100 will not be avoided :) It is a hard fork; it would be silly to elide discussion of these key issues.
I don't get the community's recent interest in avoiding certain topics. On Thu, Sep 3, 2015 at 7:20 AM, Btc Drak <btcd...@gmail.com> wrote: > We should avoid discussing actual hard fork/softfork deployment > methodologies when discussing blocksize proposals because deployment > is a separate issue. As a recent case in point, look at how BIP65 > (CHECKLOCKTIMEVERIFY) specifically avoided the issue of how to deploy. > That lead to a focused discussion of the functionality and relatively > quick inclusion. > > Deployment really is a separate issue than the mechanics of how BIP100 > will function after activation. > > On Thu, Sep 3, 2015 at 8:57 AM, jl2012 via bitcoin-dev > <bitcoin-dev@lists.linuxfoundation.org> wrote: > > Some comments: > > > > The 75% rule is meaningless here. Since this is a pure relaxation of > rules, > > there is no such thing as "invalid version 4 blocks" > > > > The implication threshold is unclear. Is it 95% or 80%? > > > > Softfork requires a very high threshold (95%) to "attack" the original > fork. > > This makes sure that unupgraded client will only see the new fork. > > In the case of hardfork, however, the new fork is unable to attack the > > original fork, and unupgraded client will never see the new fork. The > > initiation of a hardfork should be based on its acceptance by the > economic > > majority, not miner support. 95% is an overkill and may probably never > > accomplished. I strongly prefer a 80% threshold rather than 95%. > > > > As I've pointed out, using 20-percentile rather than median creates an > > incentive to 51% attack the uncooperative minority. > > > https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2015-August/010690.html > > > > Having said that, I don't have a strong feeling about the use of > > 20-percentile as threshold to increase the block size. That means the > block > > size is increased only when most miners agree, which sounds ok to me. > > > > However, using 20-percentile as threshold to DECREASE the block size > could > > be very dangerous. Consider that the block size has been stable at 8MB > for a > > few years. Everyone are happy with that. An attacker would just need to > > acquire 21% of mining power to break the status quo and send us all the > way > > to 1MB. The only way to stop such attempt is to 51% attack the attacker. > > That'd be really ugly. > > > > For technical and ethical reasons, I believe the thresholds for increase > and > > decrease must be symmetrical: increase the block size when the > x-percentile > > is bigger than the current size, decrease the block size when the > > (100-x)-percentile is smaller than the current size. The overall effect > is: > > the block size remains unchanged unless 80% of miners agree to. > > > > Please consider the use of "hardfork bit" to signify the hardfork: > > > > > https://www.reddit.com/r/bitcoin_devlist/comments/3ekhg2/bip_draft_hardfork_bit_jl2012_at_xbthk_jul_23_2015/ > > > > https://github.com/jl2012/bips/blob/master/hardforkbit.mediawiki > > > > Or, alternatively, please combine the hardfork with a softfork. I'm > > rewriting the specification as follow (changes underlined): > > > > Replace static 1M block size hard limit with a floating limit > ("hardLimit"). > > > > hardLimit floats within the range 1-32M, inclusive. > > > > Initial value of hardLimit is 1M, preserving current system. > > > > Changing hardLimit is accomplished by encoding a proposed value within a > > block's coinbase scriptSig. > > > > Votes refer to a byte value, encoded within the pattern "/BV\d+/" > Example: > > /BV8000000/ votes for 8,000,000 byte hardLimit. If there is more than one > > match with with pattern, the first match is counted. > > Absent/invalid votes and votes below minimum cap (1M) are counted as 1M > > votes. Votes above the maximum cap (32M) are counted as 32M votes. > > A new hardLimit is calculated at each difficult adjustment period (2016 > > blocks), and applies to the next 2016 blocks. > > Calculate hardLimit by examining the coinbase scriptSig votes of the > > previous 12,000 blocks, and taking the 20th percentile and 80th > percentile. > > New hardLimit is the median of the followings: > > > > min(current hardLimit * 1.2, 20-percentile) > > max(current hardLimit / 1.2, 80-percentile) > > current hardLimit > > > > version 4 block: the coinbase of a version 4 block must match this > pattern: > > "/BV\d+/" > > 70% rule: If 8,400 of the last 12,000 blocks are version 4 or greater, > > reject invalid version 4 blocks. (testnet4: 501 of last 1000) > > 80% rule ("Point of no return"): If 9,600 of the last 12,000 blocks are > > version 4 or greater, reject all version <= 3 blocks. (testnet4: 750 of > last > > 1000) > > Block version number is calculated after masking out high 16 bits (final > bit > > count TBD by versionBits outcome). > > > > Jeff Garzik via bitcoin-dev 於 2015-09-02 23:33 寫到: > >> BIP 100 initial public draft: > >> https://github.com/jgarzik/bip100/blob/master/bip-0100.mediawiki [1] > >> > >> Emphasis on "initial" This is a starting point for the usual open > >> source feedback/iteration cycle, not an endpoint that Must Be This > >> Way. > >> > >> > >> > >> Links: > >> ------ > >> [1] https://github.com/jgarzik/bip100/blob/master/bip-0100.mediawiki > >> > >> _______________________________________________ > >> bitcoin-dev mailing list > >> bitcoin-dev@lists.linuxfoundation.org > >> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev > > > > > > _______________________________________________ > > bitcoin-dev mailing list > > bitcoin-dev@lists.linuxfoundation.org > > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev > > >
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