Децентрализованные приложения. Технология Blockchain в действии

by Siraj Raval, С. Равал

Take advantage of Bitcoin s underlying technology, the blockchain, to build massively scalable, decentralized applications known as "dapps." In this practical guide, author Siraj Raval explains why dapps will become more widely used and profitable than today s most popular web apps. You ll learn how the blockchain s cryptographically stored ledger, scarce-asset model, and peer-to-peer (P2P) technology provide a more flexible, better-incentivized structure than current software models.

Once you understand the theory behind dapps and what a thriving dapp ecosystem looks like, Raval shows you how to use existing tools to create a working dapp. You ll then take a deep dive into the OpenBazaar decentralized market, and examine two case studies of successful dapps currently in use.Learn advances in distributed-system technology that make distributed data, wealth, identity, computing, and bandwidth possibleBuild a Twitter clone with the Go language, distributed architecture, decentralized messaging app, and peer-to-peer data storeLearn about OpenBazaar s decentralized market and its structure for supporting transactionsExplore Lighthouse, a decentralized crowdfunding project that rivals sites such as Kickstarter and IndieGogoTake an in-depth look at La Zooz, a P2P ridesharing app that transmits data directly between riders and drivers"

Genres: Computer Science, Technology, Finance, Programming, Nonfiction

Paperback

First published November 25, 2015

Reviews

[Alex · Rating 1 out of 5]

This book was a train wreck. It reads more like an increasingly incoherent set of blog posts than anything approaching a technical reference work. The fault seems to lie both with the author, who doesn't seem equipped for the task of sticking with a technical theme and explaining its implications for his topic, and with the (lack of) editors -- there must have been zero editorial control on this book. It jumps randomly from topic to topic towards the end, the author asks rhetorical questions and then states that he is confused as part of the text, content does not match section headers, code formatting is completely off, etc. O'Reilly should honestly feel ashamed for putting this garbage out in the state it was in.

[Gregory Zinchenko · Rating 1 out of 5]

Парень отличный и канал на Ютубе веселый. Но, если бы я купил эту книжку за бабки, то очень сильно бы пожалел. Как его здесь в чс кинуть?

[Stefan · Rating 2 out of 5]

Covers recent developments and hype around block chain but doesn't explain a thing, worth a quick scan not much more. Siraj, was the only reason for writing the book to copyright the term 'dapps'? ;-)

[Alexis · Rating 4 out of 5]

I just read the first short unedited version, but I'm really excited about where it's going (and where we're going) with all the possibilities that these technologies bring to life.

[Yonatan · Rating 1 out of 5]

The entire book is a mere 98 pages. I found the first two chapters to be interesting, with examples of decentralized, distributed applications. The rest of the book delves into different "sample" code exercises, but it's incomplete.

I did not leave with a robust understanding of Blockchain, IPFS, Proof of Contract or other concepts mentioned several times.

[Christopher · Rating 4 out of 5]

Good overview into dapps

Good overview into decentralized applications and the bitcoin/blockchain environments. Worth reading to get an understanding on how this technology could be used.

Truth be told, it is lacking on meat, but a good overview nonetheless.

[Samuele · Rating 4 out of 5]

Kerala repo is not working ( 03/04 )

[Evan Carroll · Rating 1 out of 5]

For a book with under 100 pages, I'm not sure where the fluff ends and content starts. It's horrible and filled with unexplained terminology, examples written in Go, lengthy documentation from the author's own unmaintained library, bad links, and unrelated applications.

First, I consider it a grave mistake on the publisher to allow any author to publish the documentation for their own library or examples that use their library when the book isn't self-titled by that name. The author's library is github.com/llSourcell/kerala. In the book, it's cited improperly as llSourcell/go-kerala/kerala. This is confirmed in the online errata. The kerala library has 1 contributor (the author), 0 forks, and the last commit to it was over 15 months ago. The use of kerala is prime to the entire third chapter "Building Your First Dapp" which is central to the book. I don't care about the author's dead project. Aside from that, I think though I'm not certain, the author is simply hosting the index page using Go's web server. That's not exactly decentralized. It has a single point of failure. Yes, each tweet is immutable and stored on IPFS but the index page is the tricky part and he skirts the whole issue while wasting the chapter documenting his own library.

OpenBazaar and Lighthouse get their own chapters. But what is the chance that a user for these two projects will also be in the market for making their own Dapp using a library and a series of API's? This book muddles the distinction between user and developer. All that ties these subjects together is the hype of being "Dapp", a term the author seemingly fabricates "the best way to dive into why I've chosen the term Dapp [...]".

The hypothetical questions that guide the sections are laughably silly, "Any app can be open source, so why aren't they?" Why is there a section on open source at all? What does that have to do with distributed applications? Who is attracted to Decentralized Applications and needs space wasted to explain a high level overview of the pros of Open Source?

Many of these conceptual categories are arbitrary: I can't see the tie-in on page 13. It has a graphic of conceptual types of organizations that utilize internal and no-internal capital. Why are we mapping AI's and Robots in this book? The chart on page 24, "Political cryptocurrency beliefs" is just as random -- and what is "hyperbitcoinization"? Page 27 goes into another abstract category with "Zooko's triangle" which I believe is even factually incorrect as the author relates it to OpenID; I'm not sure what the author is exactly referring to when he calls OpenID "human meaningful."

The section on decentralized computing is a bump for Heroku which the author agrees has a central point of a failure and isn't a Dapp. Other notable non-candidates include primecoin and gridcoin which "aren't utilizable for computations that users decide; they're based on existing computations that the coins' creators need." Fascinating. And, from the computer science side of this how could you possible assess a cost to NP problems except on clock cycles which would make huge assumptions and require trust to the reporter (or recalculation of sort)?

The section on decentralized bandwith is just as comical. Lots of "they could" and futuristic predictions with an overview of mesh networks.

All of that said, the section that takes the cake is "Practical Decentralization" on page 36. This section has bogus legal advice suggesting that your "start your corporation as a non-profit." What does the taxing status have to do with centralization? Non-profits have an "executive director" which function in the /same/ capacity as CEOs, and they frequently make a profit. Perhaps the author intended to suggest a horizontal workers' cooperative? Other nuggets that I would suggest you never do: "in your legal documents, label your assets as app tokens to unlock features." Cute. What's the purpose? This section also includes the hypothetical creation of a tool "bpm" the Blockchain Packet [sic] (presumably "package" not "packet") Manager. The authors imagination knows no bounds. This is perhaps the first fiction book published by O'Reilly.

I can't see a use for this book. There isn't a satisfactory explanation of "distributed hash table", "ledger", "proof-of-work", "proof-of-stake", "blockchain" or "smart contracts." Instead, these words are left vague and frequently used in such a fashion to make the entire book look like marketing hype. This is the kind of text I would expect from an author who markets himself as a "traveler, musician, postmodernist, and scuba diver."

[Peter Aronson · Rating 2 out of 5]

This book is rather sketchy, by which I mean it is short, covers some topics lightly, and others not at all. Chapter 6 (on La'Zooz) seems to actually be missing text in places -- it jumps right from a discussion of Uber to how La'Zooz tokens work without any real explanation of La'Zooz. It also lacks any summing up or conclusions. It is at its most vague when talking about why you might want to build an Decentralized Application (dapp) instead of a more conventional one, aside from vague verbiage about points of failure, privacy and government spying (and which the author later admits that most people don't care about). Nor does it really discuss the weaknesses of Decentralized Applications, such as the difficulty of remediation when something goes wrong (which is particularly odd given that one of the Decentralized Applications described in its own (short) chapter, OpenBazaar, spends a great deal of effort to solve exactly that problem, which the author actually discusses).

It's early days for Decentralized Applications, but it seems like every single Dapp described in this book other than Bitcoin is significantly incomplete, and many of them a waiting not only on coding work to be done, but on research to be successfully completed. It makes the entire field seem very tentative. Also, the author's instance on issuing and selling tokens (crypto-currancy) as the only way for Decentralized Applications to pay for themselves seems like a failure of imagination.

As for the Decentralized Application building examples and analysis of existing Dapps; understanding those require a certain amount of technical background -- say, that that might be gained by reading and understanding Mastering Bitcoin: Unlocking Digital Cryptocurrencies or the equivalent. The code examples are extremely limited, and not very clear nor necessarily well selected. The choice of Decentralized Applications to examined in detail is kind of disappointing -- surely there are some interesting Dapps out there that are not decentralized re-implementations of existing non-decentralized software with huge first-mover advantages?

There is some useful information here -- I particularly liked the description of arbitration in OpenBazaar -- but it best used a direction for further research rather than a complete description of anything.