[sbuttgereit]

This.

When I see something like this:

https://techcrunch.com/2018/09/24/walmart-is-betting-on-the-...

I just don't get it.

I understand the motivation behind them wanting this sort of broad supply-chain tracking, but I don't see what "blockchain" actually solves for them that can't be more readily/efficiently solved in other ways.

A trusted third party, with an immutable transaction ledger, and a simple to develop to set of APIs seems far superior from a product perspective in a case like this rather than those solutions that will simply build this same thing on "blockchain" software. The only gap is an API which is domain specific (like for food supply chain).

(And even this won't solve many of the trust issues in food supply chain, but it looks like it will offer the same useful traits of a blockchain only more simply).

[edit for clarity]

[Alex3917]

> A trusted third party

What does an industry with thousands of different major players have to gain by coming together to give a single company a monopoly over their entire industry? And in fact, one of the biggest strengths of blockchain is that it provides a viable alternative to monopolies for various industries.

[michaelmior]

I don't think the parent was suggesting there be a single trusted third party.

[darawk]

> A trusted third party, with an immutable transaction ledger

This is overall great. QLDB is necessary for a lot of things, and it will be useful for a lot of the stupid 'blockchain' projects to be displaced by a better technical solution.

Now cryptocurrencies and blockchains are exactly what they are: a decentralized version of this. I believe that decentralization has some use cases that are extremely important. Now it can stand on its own, without being conflated with verifiable ledgers.

[qyv]

Using a private blockchain has the same issue of trusting a third party. As soon as someone has control of who can write to the ledger, you need to trust them, period.

[Kinnard]

A lot of people would assert that "private blockchain" is an oxymoron. The semantics have not resolved yet.

I expect that they will resolve to exclude such things.

[petra]

Well AWS is already the trusted third party for so much stuff. What's another db ?

[dogma1138]

Ask the financial industry e.g. Swift.

[iblaine]

The idea is immutable micro-transactions to track operations in a complex inventory system. Consider a situation where a customer finds a nail in their banana. This 'blockchain' db could be used to recognize where the banana was sold, what truck delivered it, where that specific banana and was sourced.

It can be an interesting solution or vaporware depending on your level of interest. I personally think micro-transactions and blockchain do not go well together but reading debates about the tech is still interesting.

[dogma1138]

Assuming no bad actors what’s the difference between this and a single DB that simply tracks the banana?

A blockchain won’t solve the problem of creating a unique identifier for each banana and ensuring it was correctly scanned.

Also this isn’t a good example fundamentally because the banana is not immutable as in anyone can swap the barcode from one banana with another or it can fall off.

Blockchains really only work when everything is immutable.

[iblaine]

> Assuming no bad actors

Blockchain gives you security against bad actors. Here's a similar use case for a marijuana supply chain: https://www.nasdaq.com/article/leveraging-blockchains-to-tra...

[root_axis]

Unsurprisingly, the article provides zero details as to how a blockchain actually solves any problems here. Frankly, it's very obviously useless for all "supply chain" related ideas. If you're going to do something illegal why would you record it in a blockchain?

[baxtr]

What’s the advantage over a centralized system?

[sbuttgereit]

You have many vendors that handle the product. The farm, multiple distributors, and transportation companies.

Having a consolidated/consistent view of transactions from the full supply chain relative to tangible product could be genuinely helpful for reducing errors that could be consequential from a food safety perspective. It's unlikely to stop cheating since many of these food vendors will almost certain being humans entering transactions at keyboards (and then when you can get compliance with that transaction entry) and at those points all you can do is make cheating harder.

The challenge is how to get that consolidated/consistent view of the world across disparate parties, some of which don't know all of the other parties involved, in a secure enough manner, and in a way that the supply chain participants will be willing to take part in.

Larger players, like Walmart, can set the stage for some of that cooperation to happen just because of their relevance to the market. The government agencies that buy food also want that and also are pushing for it (that's where my clients are getting some pushes in that direction). None of that means the end goal will be achieved for any number of reasons, including many that are not technical in nature... "blockchain" just complicates those odds.

[baxtr]

So you’re saying blockchain won’t help too much?

[sbuttgereit]

Pretty much.

There are attributes of blockchain implementations which are desirable attributes to solve this problem, but they can exist outside of block chains.

In fact, it's part of why I find this Quantum product interesting for this... they seem to have those qualities that would be helpful without bring much of the other baggage.

The only thing that's not clear is how you handle authority (who says who can participate, for example). So I don't think this Amazon approach is the complete answer, but this sort of approach seems like a path which might bear more fruit than trying to implement blockchains for the problem.

[antaviana]

Inmutability of the transaction history.

[dogma1138]

You don’t need a blockchain for that also if the “transcation data” itself is not immutable such as in the case of a banana so how would this work exactly?

[sbuttgereit]

The transaction data should be immutable; many of the actual facts concerning the Banana are not mutable: it was picked when it was picked, it was moved when it was moved. Assuming the transactions reflect this accurately, they need not be mutable. What the transaction data should not be is irreversible. So, for example, if there's a data entry error discovered, I need to show that I'm changing the current knowledge of that banana without losing the prior erroneous transaction. It's the same sort of thing we'd do for a financial ledger: we don't change existing erroneous records in the database... we book new correcting records.

In a number of your comments you talk about errors: the transaction processing technology being discussed will not address those issues be they mistakes, non-compliance, or anything other that rather naive cheating.

I think people hear about some of the attributes of blockchain, such as being distributed, and say, "hey, that solves some of the problem of getting disparate, unrelated parties transacting in a common data set."... along with a misunderstanding of trust model and its relationship to data integrity across that shared ledger... and they get all excited about blockchain.

You're right you don't need blockchain and a central database could do it. The harder parts are administrative around the many parties and then getting the parties to participate at all. I think the transnational immutability aspects are beneficial for food safety, I don't think the raw complexity of implementing a new blockchain to do it makes sense.

I do think with the right kind of industry focused solution on top of something like this Amazon product, can be that sort of single database, with some of the helpful parts that have appeal in regards to blockchain and without the complexity. There are still issues which I don't believe something like this Amazon product solves, but I do think it moves the needle.

[acjohnson55]

The Walmart thing is just PR. I doubt it's anything beyond a pilot and it's probably just a permissioned ledger, much like QLDB.

[sbuttgereit]

I work with a couple of food industry businesses which are also in business with some of the other members of the Walmart initiative.

The specific technology the Walmart group is working with is IBM's implementation of: https://www.hyperledger.org/about

There is a concerted effort from what we can see, and are getting some subtle hints that we need to be going down this path from some shared government customers. That is far from saying that this will be successful or that it will get past early stages, but they're definitely trying.

Having said all that, my understanding is this is more in line with a true blockchain effort rather than something like QLDB (though I hope I've misread on that count in case I do get stuck on dealing with this).