Tier Nolan <tier.no...@gmail.com> writes: > On Sat, May 16, 2015 at 1:22 AM, Rusty Russell <ru...@rustcorp.com.au> > wrote: >> 3) ... or maybe not, if any consumed UTXO was generated before the soft >> fork (reducing Tier's perverse incentive). > > The incentive problem can be fixed by excluding UTXOs from blocks before a > certain count. > > UTXOs in blocks before 375000 don't count.
OK. Be nice if these were cleaned up, but I guess it's a sunk cost. >> 4) How do we measure UTXO size? There are some constant-ish things in >> there (eg. txid as key, height, outnum, amount). Maybe just add 32 >> to scriptlen? >> > > They can be stored as a fixed digest. That can be any size, depending on > security requirements. > > Gmaxwell's cost proposal is 3-4 bytes per UTXO change. It isn't > 4*UXTO.size - 3*UTXO.size He said "utxo_created_size" not "utxo_created" so I assumed scriptlen? > It is only a small nudge. With only 10% of the block space to play with it > can't be massive. But you made that number up? The soft cap and hard byte limit are different beasts, so there's no need for soft cost cap < hard byte limit. > This requires that transactions include scriptPubKey information when > broadcasting them. Brilliant! I completely missed that possibility... >> 5) Add a CHECKSIG cost. Naively, since we allow 20,000 CHECKSIGs and >> 1MB blocks, that implies a cost of 50 bytes per CHECKSIG (but counted >> correctly, unlike now). >> >> This last one implies that the initial cost limit would be 2M, but in >> practice probably somewhere in the middle. >> >> tx_cost = 50*num-CHECKSIG >> + tx_bytes >> + 4*utxo_created_size >> - 3*utxo_consumed_size >> >> > A 250 byte transaction with 2 inputs and 2 outputs would have an adjusted >> > size of 252 bytes. >> >> Now cost == 352. > > That is to large a cost for a 10% block change. It could be included in > the block size hard fork though. I don't think so. Again, you're mixing units. > I think have one combined "cost" for > transactions is good. It means much fewer spread out transaction checks. > The code for the cost formula would be in one place. Agreed! Unfortunately there'll always be 2, because we really do want a hard byte limit: it's total tx bytes which brings most concerns about centralization. But ideally it'll be so rarely hit that it can be ~ ignored (and certainly not optimized for). Cheers, Rusty. ------------------------------------------------------------------------------ One dashboard for servers and applications across Physical-Virtual-Cloud Widest out-of-the-box monitoring support with 50+ applications Performance metrics, stats and reports that give you Actionable Insights Deep dive visibility with transaction tracing using APM Insight. http://ad.doubleclick.net/ddm/clk/290420510;117567292;y _______________________________________________ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
