I've been pushing for greater modularization since I first got into bitcoin. I got quickly frustrated when I was only able to get through very few things (i.e. moving core structure serialization classes to a separate unit not called main). Working on Bitcoin has an added layer of frustration that goes beyond most open source projects: even though we're clearly in userland working at the application layer, a good layered protocol design is still lacking. We have no standards process separate from what basically amount to updates to one specific reference implementation. And we all need to agree on any major change, since a blockchain that is easily forked in contentious ways pretty much defeats its own purpose.
I went off to develop my own stack, where I could more easily avoid politics and focus on engineering. But I now understand the politics are inevitable. Bitcoin is inherently a cooperative project. Several people have poured themselves passionately into the reference codebase, most of whom did it (at least initially) purely as unpaid volunteers. There's a lot of love that's gone into this. But it's become pretty clear that the modularization is no longer merely a matter of good engineering - it is essential to resolving serious political challenges.
Perhaps the most frustrating thing of all is watching people pushing for relatively superficial yet highly controversial changes while we still lack the proper infrastructure to handle these kinds of divergences of opinion without either stagnating or becoming polarized.
I could continue working to reimplement an entire stack from scratch, as several others have also done - but besides the serious effort duplication this entails, it doesn't really seem like it will ultimately be a convergent process. It's too easy to let ego and habit dictate one's preferences rather than rational engineering considerations.
I know that some might feel I'm just preaching to the choir, but we should probably take a step back from implementation hackery and try to specify some core protocol layers, focusing on interfaces. Specifically, we need a consensus layer that doesn't try to specify networking, storage, wallets, UI, etc. Let different people improve upon these things independently in their own implementations. What matters is that we all converge on a common history and state. At the same time, let's open up more competition on all these other things that are separate from the consensus layer.
If only we were to dedicate a fraction of the effort we've put into this whole block size circus into what's actually important...and I blame myself as well...
On Aug 21, 2015, at 21:46, Jorge Timón <jtimon@jtimon.cc> wrote:On Thu, Aug 20, 2015 at 10:35 AM, Tamas Blummer <tamas@bitsofproof.com> wrote:Every re-implementation, re-factoring even copy-paste introduces a risk of disagreement,
but also open the chance of doing the work better, in the sense of software engineering.
But you don't want something better, you want something functionally identical.
You may want to watch sipa's explanation on why "the implementation is
the specification" and the reasons to separate libconsensus:
https://youtu.be/l3O4nh79CUU?t=764I do want something better, but not for the focus you have.Not because what you produce was not high quality, but because quality is achieved at a veryhigh cost and is hard to uphold over generations of developer. You focus on a single use casewhile there are many out there for distributed ledgers.I think in an infrastructure for enterprise applications, building consensus on the ledger is acornerstone there, but is only a piece of the solution. I built several commercially successfuldeployments where I delegated the consensus building to a border router, a Bitcoin Core,then interfaced that trusted peer with my implementation that accepted Core’s decisionsin an SPV manner. One might think of this setup as wasteful and unsuitable for “small devices”therefore an example of centralization people here try to avoid.Enterprises have sufficient resources. Solving the business problem is valuable to them even atmagnitudes higher cost than a hobbyist would bear.For mainstream adoption you need to get enterprises on board too, and that is what I care of.Enterprises want code that is not only high quality, but is easy to maintain with a developmentteam with high attrition. One has to take whatever help is offered for that, and one is modernlanguages and runtimes.Bits of Proof’s own implementation of the scripts was not practically relevant in my commerciallysuccessful deployments, because of the use of a border router, but it helped development,enabling easier debug and precise error feedback esp. end even after Core had a reject message.I integrated libconsensus only for the hope that is significantly fastens application side tx verification,which it has turned out it does not, until secp265k1 is integrated.I would likely use an other extended libconsensus too, but do not think there was a dependency onthat for enterprise development.It would help there more to have a slim protocol server, no wallet, no rpc, no qt but a highperformance remoting API.Since you already depend on libconsensus for VerifyScript, wouldn't it
be nice that it also offered VerifyTx, VerifyHeader and VerifyBlock?
You would still have complete control over storage, concurrency,
networking, policy...
My plan is for the C API to interface with the external storage by
passing a function pointer to it.Storage and validation is non-trivially interconnected, but I now the separation can be done,since I did it.Excuse me, but function pointers is a pattern I used in the 80’s. I know that they are behindthe curtain of modern abstractions with similar use, I still prefer not to see them again._______________________________________________Tamas Blummer
bitcoin-dev mailing list
bitcoin-dev@lists.linuxfoundation.org
https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev