I've only really just started looking into Hyperledger Fabric and have been asked to create an e-commerce platform (e-bay style) that uses the platform.
However, I am stuck with defining the appropriate architecture for the Hyperledger network, or if it is even appropriate to for this scenario, mainly because I do not know the number of organisations that will be part of the network at the start. Also how would this work having a single client on the front-end that users (in this case they would be organisations) would use to login, register, etc and how would this reflect on the Hyperledger network?
Would each new user be a new node on the network?
I first thought I could create a base network with just a ETCDRAFT orderer, a Fabric CA node, CouchBase, Fabric CLI node and a main Channel, and then add new organisations as they came along, but I wouldn't have anywhere to store the chain code as far I understand it.
I also thought of having the same structure but with an additional Peer node that would essentially represent the e-commerce platform itself, and new organisations (users on the ecommerce platform) would be added as users on the network, but that kind of defeats the purpose of a network in my view.
I know this might be a noob question but I am struggling a bit to define my initial set-up so that I can start writing the chain code, API and client, so any clarity on how this should ideally look in terms of network structure would be much appreciated.
The problem statement is quite vague in itself.
I am trying to answer the question with my assumptions.
Let consider e-commerce website like Amazon.
How many participants in there of blockchain network?
The sellers and buyers consider them as identities of a single organization not "Node".
The peers would be the various department running in the amazon like dep1,dep2 etc.
Related
For the past few days i am trying to learn blockchain, more specifically in using hyperledger fabric
However, while i am quite familiar building centralized app, i am so new in grasp this whole new concept, and got some question in mind i haven't found answer, yet.
If its decentralized, does the script will run as desktop background process in every machine connected to the network through internet?
Since
no way it could be "decentralized" if its hosted on 3rd party server
blockchain platform seems could seamlessly write/read local files, which certainly not possible at the case of hosted in 3rd party server
existing blockchain application (i.e bitcoin) written for desktop (c++)
If it does desktop process, in the case of creating website interface to run the application, do we need API to communicate? And if so, how the API could be made to communicate between all machine in the network?
Moreover in the case of storing sensitive data like password, since its stored locally in every machine, does it means we will rely only on encryption being used? I assume common AES256 will work? Or need multi layer encryption (as in XMR) to make it harder for people trying to decrypt those sensitive information?
Any input is greatly appreciated. Thank you in advance!
I'll answer your questions for Hyperledger Fabric since that's what you tagged this post for.
Presumably the "script" you mean is chaincode, the blockchain back-end part of the decentralized application. It runs on endorsers (part of Fabric peers), specifically all endorsers that are specified in the endorsement policy and have installed the chaincode. The endorsement policy specifies how many endorsers need to agree for chaincode transactions to go through, i.e. 3/5. These peers can be hosted by multiple organizations in different places, that's why it's decentralized.
You need to use the Hyperledger Fabric SDK to communicate with your chaincode (get data, send transactions).
Decentralized apps don't really use user-password combo for identity management. Users have public/private keypairs which they need to keep locally. Only if you want to encrypt the private key you'd need a password for the user to decrypt it locally. You use the private key to sign transactions and to authenticate with the network (which determines your access rights, i.e. user vs admin)
I can recommend the Fabric paper as a learning resource
Also check out the docs, they cover many of your questions
I would recommend first taking a step back and finding out what are the best use cases for Web3 vs Web2. There are a number of projects that seem to have been shoehorned into using Web3 when they could have been created more quickly and efficiently using
Web2 technologies.
Ask yourself these questions before jumping on board the decentralized Web3 bandwagon:
Is an Immutable Ledger the Best Fit for Your Back-end?
Does Your Back-end Work Best as Decentralized Computing?
Do You Need Scalability or High Transaction Volumes?
Only when you understand the problem you are trying to solve, can you determine the best technologies for the job.
To help answer the above questions, you can use the following article as a resource: https://www.scalablepath.com/back-end/choosing-web3-for-software-project
I have a problem with understanding why Hyperledger Fabric (HLF) uses blockchain structure.
I know that in Bitcoin blockchain structure ensures big security due to PoW algorithm and longest chain rule, but what are advantages of using a blockchain structure in HLF?
It seems to me that in Hyperledger Fabric, instead of the blockchain structure, there could be one transaction history log and network could work in the same way - I bet I'm wrong, but I haven't been able to find an explanation yet.
I would be grateful for the clarification of this issue.
I think a lot of questions you have in your mind comes from the overlapped definitions of DLT and blockchain.
DLT:
A DLT is simply a decentralized database that is managed by various participants. There is no central authority that acts as an arbitrator or monitor. As a distributed log of records, there is greater transparency – making fraud and manipulation more difficult – and it is more complicated to hack the system.
All of this could well be familiar because it’s written about the features of blockchain as well.
Blockchain:
Blockchain is nothing else but a DLT with a specific set of features. It is also a shared database – a log of records – but in this case shared by means of blocks that, as the name indicates, form a chain. The blocks are closed by a type of cryptographic signature called a ‘hash’; the next block begins with that same ‘hash’, a kind of wax seal. That is how it is verified that the encrypted information has not been manipulated and that it can’t be manipulated.
DLT platforms that are not blockchain provide immutability too, but it's just the way Hyperledger Fabric provides this characteristic which makes it a blockchain framework.
Every blockchain framework, be it the Ethereum, Bitcoin, etc all store the transaction information in blocks, where each block is linked to its predecessor by a hash and provides immutability.
Corda is very much similar to Hyperledger Fabric, but it is said to be both a blockchain and not a blockchain. Architecturally, it's very much similar to Hyperleder Fabric, but with only a key difference which makes Hyperledger Fabric a blockchain framework, and Corda a DLT.
I'll try to answer your question by emphasizing on the point that why Corda is not a blockchain.
Why is Corda a blockchain, and not a blockchain?
A Transaction in Corda is cryptographically linked (chained) to the transactions it depends on. Just like Bitcoin, but the range of concepts that can be expressed is far wider.
Transactions in Corda are processed by having each participant in the transaction execute the same code deterministically to verify the proposed updates to the ledger. Just like Ethereum, but the languages you can use are high-level and productive, like Java, rather than obscure ones like Solidity.
Transactions in Corda are shared only with those who have a need to know. Just like channels in Fabric but designed in from day one and fully integrated into the programming model.
Transactions in Corda are confirmed through a process of consensus forming using one of a range of algorithms, including Byzantine Fault Tolerant algorithms. Just like any other blockchain, but with the unique features that a Corda network can support multiple different consensus pools using different algorithms.
So, for all intents and purposes, Corda is a blockchain. And yet… there’s also an utterly critical difference.
Unlike the platforms mentioned above, Corda does not periodically batch up transactions needing confirmation — into a block — and confirm them in one go. Instead, Corda confirms each transaction in real-time. No need to wait for a bunch of other transactions to come along. No need to wait for a “block interval”. Each transaction is confirmed as we go.
Now coming onto your question why Hyperledger Fabric (HLF) uses blockchain structure? The answer is simply because they chose to.
References:
https://www.bbva.com/en/difference-dlt-blockchain/
https://cointelegraph.com/news/what-is-the-difference-between-blockchain-and-dlt
https://www.corda.net/blog/corda-top-ten-facts-7-both-a-blockchain-and-not-a-blockchain/
To keep the record immutable, Hyperledger Fabric uses blockchain structure. So by using Hyperledger Fabric, you can get an immutable record of all the transactions which is tough to temper with fraudulent activities.
Suppose you buy an valuable asset and you are the current owner of that asset. Now it is very hard for others to temper that records or change your ownership without your permission as Hyperledger Fabric uses blockchain structure to keep the record immutable.
Hyperledger Composer is a platform for accelerating the development process of Business Network Application. Why is it deprecated and what are the alternatives to composer for development of BNAs?
According to IBM, there are following three problems with Hyperledger Composer:
Composer has been designed from the start to support multiple blockchain platforms, not just Fabric - but this design has come at a cost. This design has meant that there are two completely different programming models - the Fabric programming model (chaincode) and the Composer programming model (business networks). This has caused significant confusion to users, with them needing to make a "choice" between the two programming models, with very few similarities between the two. In this particular case choice has been a bad thing, with many users opting not to use the "optional" part past the initial exploration or POC stage.
This design has also made it a lot harder for us to adopt and expose the latest Fabric features. For example, one of the questions we are constantly getting at the moment is "when can I use the Fabric v1.2 private data feature with Composer?". Whilst we've taken some steps (getNativeAPI) to assist with this problem, it is extremely difficult for us to keep up with and aligned with the latest features in Fabric when we are trying to maintain a design that keeps us blockchain platform independent. This has meant that users have understandably stopped using Composer and instead have reverted to developing with Fabric.
Finally, those of you that have used Composer will likely be fans of our simple, easy-to-use APIs (JavaScript and REST) for building applications that interact with a blockchain network. There is a lot of code behind the scenes to enable these APIs that doesn't really belong in Composer. What we have ended up doing is glossing over the underlying, low-level Fabric APIs instead of pushing improvements directly into these Fabric APIs. Today it takes ~50 lines of code to submit a transaction using the Fabric APIs, whilst in Composer it takes ~5 lines of code, and that's wrong - Composer's value should not come from just making Fabric easier to use.
Please read this for details.
The only problem with Composer is that IBM, et al abandoned it. Composer was (to an extent kind of still is) an effective way for users of Fabric to proof of concept (POC) business solutions for prospective customers -- and for users wanting to justify internal budgets to attempt to deploy projects internally. Using real-world business logic.
Composer should be the business logic stack that sits on top of Fabric and allows users to deploy without having to get down into the weeds.
I don't need to know that I need an orderer or CA for every org -- but I do need to know that I have 6 orgs who will participate in my network, two of them need to communicate using private data on a separate channel from the others and I do need to know what my business use cases rules are. An automated tool or script should allow me to launch an internal network **locally* and go from there. Yes, I will need to know fabric details or have someone on hand that does to be able to tweak my networks -- but Composer let me POC these.
There is no -- as in zero -- equivalent for Fabric -- in fact there is no tool to allow one to easily clone fabric samples for their own use and easily plug in their own network / org settings.
And the IBM VS Code plugin tool is garbage if you're wanting to setup an internal, standalone network without going to the IBM cloud. Really? Seriously?
Without Composer -- or a tool like it -- investing in Hyperledger Fabric is a huge financial & resource gamble and time sink. Period. The code changes almost weekly, there are significant bugs, the community is reticent to fix what at times are glaring documentation issues and address hardware sizing issues. Not to mention the cost to assign engineers and software architects to test what is not-yet-ready-for-prime-time software. Forget the amount of time that is needed to just get familiar with the documentation and fabric components to be able to architect business-grade networks.
Regarding the points made in the answer above:
There should be two distinct programming models because the BNA approach works from a business deployment point of view. To say that having a Composer stack with it's API on top of Fabric "confuses" users is like the old saying "if the customer is too stupid to know how to use the deeply technical product the customer is too stupid" -- that's fundamentally wrong.
I shouldn't have to refresh my knowledge of combustion engines every time I get into a vehicle and press the start button -- I know where I have to go, how I will get there and know how to operate the vehicle to do so. And if I want to tweak or otherwise modify the vehicle, its engine, electrical system, etc. I get out the equivalent of fabric documentation and learn to use those tools or hire a mechanic that already knows how to use them.
And the design did not make it harder to adopt and expose the latest features of Fabric -- what the development team failed to do was to implement those features in Composer in lock step with releases of Fabric. This was a dev team deployment issue and not an end user issue. And to say -- not imply, say -- that the community didn't step up to the plate was a load of crap. If IBM wanted to support it, it could have - it has the personnel, financial and global resources to do so.
Within real-world settings the business perspective of blockchain / distributed ledger viability for enterprise applications is less than enthusiastic -- in fact it's doubtful at best. The number one compliant we get from prospects globally (NA, EMEA) is no one can adequately demo this. No kidding -- showing a prospect via a terminal window that car ownership can move from one user to another is going to solve their business needs? Really? Via a terminal window no less.
For us to POC a complex use case and be able to back of the napkin demo it we now have to write entire fabric apps or hope we can cobble through fixing a fabric samples example -- and in the process work through the bugs in samples.
We've spent hundreds upon hundreds of hours building out POC use cases only to have Composer go by the way side, Fabric version x not work with the just released Fabric version xx, have prerequisite software versions change or issues with god forbid Raft or Kafka that haven't been fully tested prior to "alpha" next greatest thing Fabric release. etc., etc, etc.
And to the writers last point above -- the value of Composer should absolutely be making Fabric easier to use for basic network stand up and POCs. No one is suggesting that getting into the weeds with Fabric is a bad thing -- but from a BUSINESS point of view having something like Composer to POC before committing to projects it's essential.
Will we continue to work with Fabric and hope that the development team catches up with real-world business needs -- probably. All those IBM and other training sessions for composer we've put employees through for the most part have been a waste.
So, from a team who is trying so very hard to justify what is good about Hyperledger and Fabric -- please don't just sack something like Composer in the future. Because we're not going to invest in personnel and train them if this is just the next big thing to go by the wayside. I have 15 teams deployed with prospects globally working prospective use cases and implementations -- trying to tweak and push customer-centric use case demos to them has been Hyperledger Fabric hell.
One persons rather small opinion. GR
I think the reasons are clear from the previous comments, but for your last question one option hundreds of devs are taking is using Convector. Convector is a Hyperledger Labs project that was created before Hyperledger Composer was deprecated but that looks similar to developers. It follows a model controller pattern (similar to Composer assets and transactions) however it compiles natively to Fabric code and does not create a runtime.
Code created with Convector can be taken to production and include all sorts of helpers like an API generator, a development environment bootstrapper (one command to create a local network), decorators for making models more predictable, unit tests by default (CI/CD friendly), tens of code samples and real-life projects to use as reference.
Convector has a community of hundreds of devs, some of them migrated from Composer rather easily, others it is the first tool they get to know for Fabric. The main difference about why Convector won't go away anytime soon even if it looks and feels similar to Composer is its decoupled architecture and capability to use and run natively with Fabric.
If you'd like to join the community there people will help you migrate from Composer to Convector. You can join here.
Here's a blog post mapping concepts from Hyperledger Composer to Convector.
Small recap about Convector:
Looks familiar to Hyperledger Composer.
Same code can be taken to production.
Run natively and scales natively with Fabric.
An ecosystem of tools: unit tests, developer environment, API generator, etc.
Great and friendly community in Discord.
--
Disclaimer: I work with Covalent, the developers of Convector. Convector is a free open source Apache 2.0 group of projects.
Both, Hyperledger Fabric and BichainDB offer the possibility to have a private, permissioned blockchain database. With their concepts they try to address the main disadvantages of public blockchains like lack of privacy and lack of performance (low throughput etc).
What are the main differences between the two technologies?
If you try out example application of both frameworks, you will quickly notice that BigchainDB is easier to start with. Hyperledger Fabric involves a lot of more knowledge to master it.
Fabric knows different kinds of nodes (peers, peers additionally being endorser nodes, orderer) and thereby allows a very flexible setup, depending on the consortium design and organisations themselves. BigchainDB has one kind of node that can be deployed. Also every involved organisation gets one node of course.
Fabric has richer capabilities to model assets and all kinds of transactions. One transaction kind can always be implemented by a custom processor function doing whatever is needed to query or modify the state of the ledger. BigchainDB only knows CREATE and TRANSFER transactions on every defined asset. You can create something (that may be also divisable, e.g. amounts of tokens) and can transfer them completely or partly.
Both seem to have pretty low level APIs. Fabric has more APIs and config models that need to be mastered. But Fabric is being complemented by frameworks such as Composer (with all its nice libraries involved, like playground and rest-server) that really improve the programming model. As far as I know there is nothing like that for BigchainDB, also because it is pretty simple from the start.
Consensus: BigchainDB uses Tendermint which is Byzantine Fault Tolerant. Fabric does PBFT which is Practically Byzantine Fault Tolerance, based on the idea of Miguel Castro.
In general I would say that Fabric is intended to be used for complex business use cases. BigchainDB is simpler and nice for assets that can be divided (financal stuff like coins/tokens maybe).
I have just started working with Hyperledger Fabric. I was looking for a tool that would demonstrate graphically the entire network and its operations.
Is there any existing project that does that?
If not, I intend to create one. Would anyone like to collaborate?
As a starting point, I am looking at using http://hyperledger-fabric.readthedocs.io/en/latest/build_network.html . I understand that it will be worth including the following:
Organizations
MSPs
CAs
Peers
Channels
(please add to this list)
Looking through the APIs, I am trying to figure out the starting point. I was hoping to find something like Client.getOrganisations() to get a list of all organisations on the network, but it doesnt seem to exist. Any ideas how to discover all Organisations using the Node SDK?
Entities in Hyperledger Fabric usually executed with Docker,Docker Swarm or Kubernetes environments, hence I'd suggest to take a look on Weave Scope project which could provide quite good visualization for your docker containers deployment.