Category

Hyperledger Fabric

Change Healthcare: 50 million transactions a day using Hyperledger Fabric

By | Blog, Healthcare, Hyperledger Fabric

Change Healthcare is on a mission to modernize the American healthcare system. A central part of that plan is extending its Intelligent Healthcare Network with blockchain technology to provide a faster, better experience for all.  

Change Healthcare operates the largest healthcare network in the country. Formed through years of mergers and acquisition, the healthcare infrastructure company links 900,000 healthcare providers and 5,500 hospitals with 2,200 government and commercial payers.

A network of this scale, built from a mix of companies, means a very complex back end with lots of systems that are working independently. To unite information and give customers faster, better access to data, Change Healthcare turned to Hyperledger Fabric to begin blockchain-enabling its Intelligent Healthcare Network.

The starting point was modeling an existing network linking providers to payers with a blockchain and then seeing if it could stand up to real-world traffic. After testing and assessing options, Change Healthcare’s launched this initial Hyperledger Fabric-powered network in January 2018. It’s been running as a parallel network since, processing as many as 50 million transactions a day—with throughput up to 550 transactions a second. That’s enough to handle all the healthcare claims activity that Change Healthcare handles across its full network.

The Hyperledger team has worked closely with Change Healthcare to document this large-scale network deployment and its performance in a detailed case study. Highlights include system criteria and planning, details on the supported workflow and transactions and future directions, including plans for ensuring interoperability, boosting throughput even further and migrating more business partners to the network.


CLICK HERE TO READ THE CASE STUDY

(3.31.2019) Packt: Installing a blockchain network using Hyperledger Fabric and Composer[Tutorial]

By | Hyperledger Fabric, News

This article is an excerpt taken from the book Hands-On IoT Solutions with Blockchain written by Maximiliano Santos and Enio Moura. In this book, you’ll learn how to work with problem statements and learn how to design your solution architecture so that you can create your own integrated Blockchain and IoT solution.

In this article, you will learn how to install your own blockchain network using Hyperledger Fabric and Composer.

View the full article here.

Developer showcase series: Juan Navarro, Biztribution

By | 网志, Hyperledger Fabric

Back to our Developer Showcase Series to learn what developers in the real world are doing with Hyperledger technologies. Next up is Juan Navarro of Biztribution.

What advice would you offer other technologists or developers interested in getting started working on blockchain?

First, I recommend having a look at Anders Brownworth’s website “how blockchain works”. It’s a very easy way to understand how and why blockchain works. Next, add some PKI infrastructure reading to know who did what and… congratulations! Now, you know the foundations of blockchain.

When it comes to Hyperledger Fabric, don’t let the seeming complexity make you reluctant to dive in. At first sight, Hyperledger Fabric may look a bit overwhelming  with a lot of different technologies and configuration files.. However, to quote Albert Einstein: “Learning is experience. Everything else is just information.” Don’t be afraid of the vast amount of documentation you can find about Hyperledger. Instead, I recommend, start with the Fabric demo. Then, watch Chaincode for developers and some of the other online examples. Suddenly, everything will begin to make sense and you will start to understand the architecture and its beauty.

Give a bit of background on what you’re working on, and let us know what was it that made you want to get into blockchain?

Our project is related to giving governance of content distribution back to airlines. Airlines are competitors and partners at the same time. For that reason, they have to share some information continuously and keep other information private. In order to achieve that today, they rely on third parties that centralize all their data to retail their contents, specifically over indirect channels. We have identified blockchain as the answer to solve this puzzle, and Hyperledger Fabric as the technology the industry needs.

What project in Hyperledger are you working on? Any new developments to share? Can you sum up your experience with Hyperledger?

We are mainly working with Hyperledger Fabric. At the moment, we have successfully done several lab proofs-of-concept with millions of routes, availabilities, fares, geographic data, etc. It is amazing to see how the information flows among peers.

What do you think is most important for Hyperledger to focus on in the next year?

  • Pluggable interfaces and documentation.
  • Performance metrics as a function of transactions/sec, peers, consensus, channels, participants, orderers, etc. It would be great to get an answer to the white paper published by the Performance and Scalability Working Group.
  • Guidelines about how many orderers we need to deploy as a function of organizations, transactions, peers, performance, etc.

As Hyperledger’s incubated projects start maturing and hit 1.0s and beyond, what are the most interesting technologies, apps, or use cases coming out as a result from your perspective?

Sovereign ID initiatives. I am very careful about sharing my personal data. I have always asked myself “why do I have to give my ID when I subscribe to a service, in hotels, shops, etc.?” Are there other alternatives that fulfill regulatory requirements and preserve my privacy at the same time?

What’s the one issue or problem you hope blockchain can solve?

Well, our goal is to reinvent an  industry by creating a new revolutionary, automated and simple distribution model for the travel and tourism ecosystem. Based on Distributed Ledger Technology, we enable airlines to regain control over their contents. This creates a shift towards a fully decentralized scenario in which flexibility and de-commoditization are achieved, translating into more efficient operations and a significant reduction in  distribution costs.

Where do you hope to see Hyperledger and/or blockchain in 5 years?

I hope to see Hyperledger in a lot of interactions on a daily basis where  end users are not even able to perceive that Hyperledger is working behind the scenes. That’s the magic of technology!

What is the best piece of developer advice you’ve ever received?

Don’t write a single line of code until you have a clear understanding of what you want to get done.

What technology could you not live without?

Short answer: Linux and… Linux!

At home, I’m a big fan of Raspberry Pi because you have a great computer with a very low energy consumption and no noise. With it, I have IPTV, home automation, VPN and content filtering for kids.

At work, micro services architecture! Once you try it, you can’t live without it!

Hyperledger Indy Graduates To Active Status; Joins Fabric And Sawtooth As “Production Ready” Hyperledger Projects

By | 网志, Hyperledger Fabric, Hyperledger Indy, Hyperledger Sawtooth

By Steven Gubler, Hyperledger Indy contributor and Sovrin infrastructure and pipeline engineer

The Hyperledger Technical Steering Committee (TSC) just approved Indy to be the third of Hyperledger’s twelve projects to graduate from incubation to active status.

This is a major milestone as it shows that Hyperledger’s technical leadership recognizes the maturity of the Indy project. The TSC applies rigorous standards to active projects including code quality, security best practices, open source governance, and a diverse pool of contributors. Becoming an active Hyperledger project is a sign that Indy is ready for prime time and is a big step forward for the project and the digital identity community.

Hyperledger Indy is a distributed ledger purpose-built for decentralized identity. This ledger leverages blockchain technology to enable privacy-preserving digital identity. It provides a decentralized platform for issuing, storing, and verifying credentials that are transferable, private, and secure.

Hyperledger Indy grew out of the need for an identity solution that could face the issues that plague our digital lives like identity theft, lack of privacy, and the centralization of user data. Pioneers in self-sovereign identity realized we could fix many of these issues by creating verifiable credentials that are anchored to a blockchain with strong cryptography and privacy preserving protocols. To this end, the private company Evernym and the non profit Sovrin Foundation teamed up with Hyperledger to contribute the source code that became Hyperledger Indy. The project has advanced significantly due to the efforts of these two organizations and many teams and individuals from around the world.

A diverse ecosystem of people and organizations are already building real-world solutions using Indy. The Sovrin Foundation has organized the largest production network powered by Indy. The Province of British Columbia was the first to deploy a production use case to the Sovrin Network with its pioneering work on Verifiable Organizations Network, a promising platform for managing trust at an institutional level. Evernym, IBM, and others are bringing to market robust commercial solutions for managing credentials. Many other institutions, researchers, and enthusiasts are also actively engaged in improving the protocols, building tools, contributing applications, and bringing solutions to production.

The team behind the project is excited about current efforts that will lead to increased scalability, better performance, easier development tools, and greater security. User agents for managing Indy credentials are under active development, making it easy to adopt Indy as an identity solution for diverse use cases.

If you’d like to support Indy, join our community and contribute! Your contributions will help to fix digital identity for everyone. You can participate in the discussions or help write the code powering Indy. Together, we will build a better platform for digital identity.A

Does Hyperledger Fabric perform at scale?

By | 网志, Hyperledger Fabric

I’m glad you asked! The short answer is: yes, it does indeed!

I get questions

I get a lot of questions about the performance of Hyperledger Fabric (Fabric) at scale. Often times, people have done some (or read/heard about) performance testing (say using early versions of Caliper on their laptop, or with earlier versions of Fabric) and came away with a sense that the performance was not all that great.

The Fabric maintainers readily acknowledge that prior to the release of Hyperledger Fabric v1.1.0, performance was not great. The Fabric maintainers had recognized with Fabric v0.6 that we needed to adopt a new architecture to enable the platform to achieve the performance characteristics that many potential enterprise blockchain use cases demanded. Our objective for v1.0.0 was to get a functioning version of our new architecture available to users. We did not want to get caught up in premature optimization. Since that time, we have invested considerably in performance improvements, starting with the v1.1.0 release and continuing to this day.

On my IBM-hosted blog, I’ve started a series of posts aimed at providing information on performance and scale of Hyperledger Fabric. My initial blog post on the subject started to outline some best practices to improve the performance of Hyperledger Fabric that I have gleaned from experimentation with Fabric endorsement policies, load-balancing and orderer configuration. My most recent post addresses a common misconception about Fabric’s ability to scale its channel architecture.

Does the Fabric channel architecture perform at scale?

So, does Hyperledger Fabric performance suffer with a proliferation of channels? The short answer is: not that I have observed with the latest versions of Fabric v1.4.0 and v1.4.1. I’d encourage you to hop over to my two posts above for the details.

Another interesting development that actually came as a pleasant surprise is that the introduction of Raft consensus for the Fabric ordering service has yielded a nice improvement in latency, which actually allows one to push the overall throughput to new heights while keeping the latency at acceptable levels. It also significantly reduces the operational complexity of running Kafka and Zookeeper.

While it is too early to make sweeping statements, initial testing has yielded impressive improvements in throughput while keeping latencies under a second.

Moving forward

The Fabric community continues to work on various aspects of performance. Our next release (v1.4.1-rc1 is available for testing now) will focus on the addition of Raft consensus mentioned above. The next release, v2.0, will include a state database cache that should realize an overall performance improvement in accessing the state database.

Following on that, we will be working on releasing the lock on the state database once the cache has been updated to reduce lock contention and enable even greater throughput. We are receiving great insights and recommendations from members of the community who are focused on the performance of Fabric, and gradually we hope to leverage that learning in subsequent releases this year.

Of course, the Fabric maintainers are always interested in having new (and old) members contribute to improving Fabric. Performance is just one area to engage -.there are  myriad other ways to contribute as well., Feel free to reach out in Chat (#fabric) or in email (fabric@lists.hyperledger.org).

Hyperledger Welcomes Nine New Members to its Expanding Enterprise Blockchain Community

By | Announcements, Hyperledger Fabric, Hyperledger Indy

Advances Collaboration with Growing Portfolio of Working Groups and Cross-Industry Special Interest Groups

SAN FRANCISCO (March 27, 2019) Hyperledger, an open source collaborative effort created to advance cross-industry blockchain technologies, today announced that nine organizations  have joined the community. The new members, which includes the first general members from Malaysia and Saudi Arabia, further strengthen the global support for the leading enterprise blockchain project.  

Hyperledger is a multi-venture, multi-stakeholder effort hosted at the Linux Foundation that includes various enterprise blockchain and distributed ledger technologies. With the support of its fast-growing and increasingly diverse community, the organization announced the expansion of its portfolio of Special Interest Groups (SIGs), with the addition of the Hyperledger Social Impact SIG, Hyperledger Trade Finance Special Interest Group and, most recently, Telecom SIG. Hyperledger also welcomed the Smart Contract Working Group. Additionally, Hyperledger released two case studies offering a detailed look at Walmart’s unprecedented advancement of the food supply chain industry using Hyperledger Fabric and British Columbia’s efforts to cut government red tape with Hyperledger Indy.

“Our growing line-up of members and cross-community and cross-industry groups all point to the value of collaborative development, particularly for enterprise blockchain technologies,” said Brian Behlendorf, Executive Director, Hyperledger. “As our Walmart and British Columbia case studies demonstrate, blockchain creates common ground for a network of stakeholders, adding value for everyone in the process. We view our community-based, open source approach in the same light, encouraging cross-industry collaboration at every turn. We welcome our newest members and look forward to their contributions to the community’s efforts.”

Hyperledger allows organizations to create solid, industry-specific applications, platforms and hardware systems to support their individual business transactions by offering enterprise-grade, open source distributed ledger frameworks and code bases. The latest general members to join the community are Altavoz, Flowchain, Limar Global, PeerNova, Inc., Quant Network, ReGov Technologies Sdn. Bhd, Securitize and Silicon Valley Bank.

Hyperledger supports an open community that values contributions and participation from various entities. As such, pre-approved non-profits, open source projects and government entities can join Hyperledger at no cost as associate members. Associate members joining this month include Auburn University RFID Lab.

New member quotes:

Altavoz

“When Altavoz began accepting Bitcoin in 2013, we came to understand the importance of blockchain through the forest of cryptocurrencies,” said Altavoz CEO Nelson Jacobsen. “This led to work with the entertainment trade group, MusicBiz.org, on crypto and blockchain educational issues for artists, labels and music distribution companies. Joining the Linux Foundation and Hyperledger is the right next step for the growth of blockchain in the entertainment industry, and we look forward to being a part of Hyperledger’s efforts to create an open standard for distributed ledger technology.”

Flowchain

“Flowchain is excited to be a Hyperledger member,” said Jollen Chen, founder & CEO, Flowchain. “As a distributed ledger for peer-to-peer IoT networks and real-time data transactions, Flowchain’s design and architecture achieve advanced performance in both time and messages size compared to traditional distributed ledger technologies. By joining Hyperledger, Flowchain is ready to move to the next level and build up more application scenarios for IoT and AI industries. We are also looking forward to collaborating with more open-source based teams to evolve blockchain solutions.”

Limar Global

“We are pleased to join Hyperledger and to be the first Saudi company to join this global member community,” said Abdulellah M. Alnahdi, co-founder/director of Limar Global Technology. “Our team has been inspired by the Vision of 2030 for digital transformation of our country.  Limar Global Tech aims to be a leader in the technological developments of Saudi Arabia and we realize that Hyperledger is the perfect community for our government and private sector to leverage for this digital transformation. We strive to bring forth the best for our people and working with the Hyperledger community will allow us to accelerate the use of DLT in our country. Whether its eHealth, Supply Chain management, or government services, we strive to adopt use cases that will ultimately make people’s lives easier. Our mission is to simplify life with advanced technologies and to help create a digital state that serves the greater good in our country. We look forward to collaborating with the Hyperledger community members and contributing to the greater cause of trusted networks.”

PeerNova, Inc.

We are excited to join the Hyperledger community,” said Gangesh Ganesan, PeerNova President & CEO. “Our Cuneiform® Platform is built on principles of interoperability across existing financial and market infrastructures. Joining the Hyperledger community allows us to continue developing a solution that works seamlessly with internal, external, and all emerging DLT networks to achieve end-to-end visibility in real-time while ensuring privacy and confidentiality.”

Quant Network

“We are honored to join Hyperledger and the Linux Foundation to contribute to open source software and provide domain expertise,” said Gilbert Verdian, CEO and founder, Quant Network. “We see the immense value of collaborating to bring mass adoption for blockchain technology and contributing with our Overledger operating system, which helps unlock the potential of blockchain technology by addressing interoperability between blockchains as well as existing networks. Our work is driven by the belief that collaboration makes the blockchain ecosystem stronger, which is why the majority of our code is open source. We believe it’s crucial to support the development of DLT solutions and Hyperledger projects for enterprises and developers. We are excited to join this community to both contribute and help customers and users around the world benefit from this transformational technology.”

ReGov Technologies Sdn. Bhd.

“We are excited to be the first general member of Hyperledger in Malaysia,” said Datuk Paul Khoo, Founder and CEO of ReGov Technologies Sdn Bhd. “The goal is to infuse and grow the capabilities of Hyperledger within the Malaysian public and private sector to build trust and accountability while streamlining processes to reduce cost. Leveraging the ecosystem of Hyperledger, ReGov will drive change using this next-generation technology to improve transparency and governance within all organisational spheres in Malaysia.”

Securitize

“At Securitize, we believe all financial products will eventually adopt blockchain,” said Carlos Domingo, CEO & co-founder, Securitize. “As a leading technology platform for financial products, we see our membership in Hyperledger as a logical, evolutionary step in order to properly provide services to financial institutions on both permission-based and private blockchains.”

Silicon Valley Bank

“We could not be more excited to join the Linux Foundation and Hyperledger and do our part to advance the Open Source community,” said Dave Kochbeck, Chief Scientist, Silicon Valley Bank. “As the leading financial services institution for the innovation economy, it is critically important that we go beyond the transaction to engage deeply in the technical communities that will help shape the future of financial services and how we work with and support our clients.”

About Hyperledger

Hyperledger is an open source collaborative effort created to advance cross-industry blockchain technologies. It is a global collaboration including leaders in finance, banking, Internet of Things, supply chains, manufacturing and Technology. The Linux Foundation hosts Hyperledger under the foundation. To learn more, visit: https://www.hyperledger.org/.

Hyperledger Unveils 17 Summer Internship Opportunities

By | 网志, Hyperledger Caliper, Hyperledger Fabric

The Hyperledger Summer Internship program is back and bigger than ever for 2019! This year, Hyperledger is offering 17 paid internship opportunities for students who want real world experience advancing open source blockchain technologies.

The line-up of internship projects are each led by active developers in the Hyperledger community and offer a fast path to becoming an active contributor to key blockchain frameworks and tools. This is your chance to:

  • Develop a close working relationship with open source professionals and industry leaders to expand your professional network.
  • Learn open source development infrastructure and tooling first hand by working closely with active developers in the community.
  • Build your resume by doing hands-on opportunity work that advances your academic and professional interests.

Each intern will be  paired with a mentor or mentors who designed the project to address a specific Hyperledger development or research challenge. The mentors will provide regular evaluations and feedback. Interns can work from anywhere, will receive stipends and be invited to travel (with expenses covered) to a Hyperledger event where they will present their work to the community.

This is the third year for the Hyperledger Internship program. It has grown quickly from six projects in the first year to 17 this summer. Many of last year’s interns shared their experiences in a blog post; see what they had to say here.

The application process is now open and the deadline to apply is April 22. You may submit your application here. Read on for descriptions of some of the projects planned for this year.

Hyperledger Caliper Visualization Project

Hyperledger Caliper is a platform for facilitating the execution of user-provided workloads/benchmarks on multiple blockchain platforms in a transparent way. Caliper achieves its flexibility by relying on two configuration files during its execution.

One configuration file describes the test rounds that Caliper must execute, including: the intensity/rate and content of the workload; the deployment of processes that generate the workload; and additional monitoring settings. The other configuration file describes the target blockchain network in detail, at least including the topology of the blockchain network (among other, platform-specific attributes).

The aim of the project is the following:

  • Create a GUI component for Caliper that makes the management of configuration files easier, specifically:
    • Assembling/generating configuration files through the GUI
    • Saving, loading and editing configuration files
    • Providing built-in documentation and tips for the users
  • Visualize in real-time the key performance indicators observed during the execution of a benchmark

IoT and DLT in a Telecom Multi-carriers Architecture Project

The three major characteristics of IoT are mobility, scalability and interoperability that play at three different levels/layers: identity, connectivity and application.

Blockchain and trusted identities enable the true potential of IoT.

Current needs:

  • Trusted IoT identities: enabling connection or communication among entities
  • Scalable connectivity
  • Interoperability of apps

The solutions:

  • Cryptographically secured identity
  • Autonomous provisioning
  • Decentralization

Task 1: 1º PoC

Using Indy to building up an IdM system taking into account the needs of an IoT architecture (mobility, scalability and interoperability) and challenges (access control, privacy, trust and performance).

a – proving basic feasibility and viability

b – proving feasibility with a real system and providing viability

Task 2:

Identify the metrics to measure the performance & scalability of a decentralized IdM for IoT

Task 3: 2º PoC

a – proving scalability to bi- parties (2 carriers) and a large amount of data

c – proving privacy and confidentiality in bi- parties (2 carriers) environment

d – exploring integration with different types of data & contract types

X.509 Certificate Transparency Using Hyperledger Fabric Blockchain Project

The security of web communication via the SSL/TLS protocols relies on safe distribution of public keys associated with web domains in the form of X.509 certificates. Certificate authorities (CAs) are trusted third parties that issue these X.509 certificates. However, the CA ecosystem is fragile and prone to compromises.

Leveraging recent advances in blockchain development, we recently proposed a novel system, called CTB (Certificate Transparency using Blockchain), that makes it impossible for a CA to issue a certificate for a domain without obtaining consent from the domain owner (See https://eprint.iacr.org/2018/1232 for a copy of the paper).

CTB (Certificate Transparency using Blockchain) proposes a Hyperledger Fabric (HF) network among the member certification authorities by requiring each certificate authority to play the role of endorsing peers and who belong to different organisations (orgs in HF vocabulary). The aim of this project is to scale up the existing proof-of-concept implementation through several stages:

  1. Development of client application for Certificate Authority organisation and Browser organisation facilitating access to the underlying fabric blockchain network.
  2. Setting up the CTB over cloud.
  3. Chrome extension for browser client application.
  4. Benchmarking CTB-assisted SSL/TLS handshake duration

Read more details on the above projects and many more here. Then check out the eligibility requirements and application steps.

Remember, applications are due by April 22 submit your application here.

If you have any questions, please contact internship@hyperledger.org. Remember, you can always plug into the Hyperledger community via github, Hyperledger Chat, the wiki or our mailing lists.

Convector: Writing an Open Source Development Framework

By | 网志, Hyperledger Fabric

Convector (a.k.a Convector Smart Contracts) is a JavaScript development framework built for enterprise blockchain frameworks. It enhances the development experience while helping developers create more robust and secure smart contract systems. It spans through the chaincode and backend all the way to the front end, allowing developers to reuse the same code base in the form of libraries. It’s based on a model/controller pattern, supports Hyperledger Fabric and runs natively along Fabric’s well-crafted patterns.

This blog post walks through the history of the project and highlights the challenges and solutions developed along the way.

Everything began when we started to work on Tellus, a code-less transaction designer written to run on a Hyperledger Fabric blockchain. Back then we had a bunch of Golang smart contracts.

Our first impression of the developer experience (DX) was not so good. There are two methods: init and invoke with no other way to add new methods other than by putting an if condition on the invoke method and using one of the parameters to indicate the method invoked. All parameters are positionally passed strings requiring complex parameters to be parsed manually and there was no way to test it locally.

At the beginning of the project, Fabric 1.1 landed adding support for Javascript chaincodes. We decided to try it out hoping for improved developer experience. Unfortunately, it follows the same pattern found in the Golang chaincodes, and you still have to do some dirty work in your everyday logic. We kept looking for a better solution and found a post about a library from TheLedger on making Fabric chaincodes in Typescript that really improves over what you have with raw Javascript.

During the migration of our smart contracts from Golang to Javascript a pattern emerged. Most of the time functions do things in the following order:

  1. Parse the arguments.
  2. Make some assertions.
  3. Perform the changes.
  4. Save the changes.

This led to a fundamental question about theproject plan: should smart contracts get migrated quickly or should more time be spent figuring out a pattern and making them flexible enough for multiple business cases. It all started in the ./src/utils/ of the project.

/** @module @worldsibu/convector-examples-token */

import * as yup from ‘yup’;
import {
 ConvectorModel,
 ReadOnly,
 Required,
 Validate
} from ‘@worldsibu/convector-core-model’;

export class Token extends ConvectorModel {
 @ReadOnly()
 public readonly type = ‘io.worldsibu.examples.token’;

 @ReadOnly()
 @Required()
 @Validate(yup.object())
 public balances: { [key: string]: number };

 @ReadOnly()
 @Required()
 @Validate(yup.number().moreThan(0))
 public totalSupply: number;

 @ReadOnly()
 @Required()
 @Validate(yup.string())
 public name: string;

 @ReadOnly()
 @Required()
 @Validate(yup.string())
 public symbol: string;
}

Figure 1 — Convector Model
Fabric does not have a restriction on the data shape stored in the blockchain. You basically have a key-value map where both are strings, which means you can serialize and store any complex object. We took apart the models to reuse them in code. We just passed all of the necessary parameters in.

@Invokable()
 public async transfer(
   @Param(yup.string())
   tokenId: string,
   @Param(yup.string())
   to: string,
   @Param(yup.number().moreThan(0))
   amount: number
 ) {
   const token = await Token.getOne(tokenId);

   if (token.balances[this.sender] < amount) {
     throw new Error(‘The sender does not have enough funds’);
   }

   token.balances[to] = token.balances[to] || 0;

   token.balances[to] += amount;
   token.balances[this.sender] -= amount;

   await token.save();
 }

Figure 2 — Convector Controller

With Fabric, you get a typed list of parameters for functions. We didn’t want to be parsing models all of the time in all of the functions, so we added some decorators to validate if all parameter type invariants were met successfully. Those parameters might be a primitive, complex or even a model.

Functions now started to look more like a controller. They handled the business logic while the model described the data.

Now came the time to integrate all of the chaincodes into our Nodejs REST API. In the process, we realized we were creating a wrapper library on the server to call my chaincodes with the fabric-client lib. This is a very common situation so we looked for a better way to automate this.

I wanted to use the same controller and model files on the server as well as on chaincode. Doing so meant decoupling the relationship between the models and the storage layer (Fabric) as well as the controllers and the execution action.

This is where we realize Hyperledger Fabric was just one of the multiple blockchains Convector can support.

Adapter and Storage come into play.

The adapter is the underlying layer for the controller. Controllers define the methods, params, and business logic while adapters deal with how to route the invocation to the right place. For example, in our API it uses an adapter to invoke the fabric-client library and send a transaction.

The storage provides the functionality to interact with the models. Whether you want to save, delete or query something, you interact with the model itself, and, behind the scenes, it interacts with the specified service. On chaincode this is the Fabric STUB object. In the Nodejs API, it might be sending a query transaction or read from CouchDB.

Pro Tip: Convector can be used with something other than a blockchain. Like, configure an adapter or a model to call an API or another database.

The weekend turned into a month of creating tools and perfecting the pattern. Here are some of the tools created in the journey that you can leverage today:

# Install the CLInpm i -g @worldsibu/convector-cli
# Create a new chaincodes projectconv new mychain -c token
cd mychainnpm i
# Install a dev environmentnpm run env:restart # Install the chaincodenpm run cc:start — token 1

Figure 3 — Convector CLI

Also, Convector already comes with a Fabric adapter, a Fabric storage, a CouchDB storage, and a mock adapter (for unit tests) that you can use to seamlessly create code for your chaincode as well for your NodeJS backend while creating tests that can be included in your CI/CD pipelines. This is critical in any real-life development.

Extra adapter and storage layers can be easily created and we’re excited to see what the community builds around these tools. At the same time we were building this, we continued working on our internal product’s migration, which helped to test the framework in real life scenarios before launching it.

I’m glad we didn’t take the easy path on this migration. We’re pretty happy with the result, and the journey of publishing an open source tool has been amazing. It’s also rewarding to see  hundreds of people using it every day.

Hyperledger Fabric is an excellent blockchain framework. The infrastructure it provides covers most of the use cases in a secure and reliable way. That’s why we think it deserves a robust interface for smart contracts too, and we want to contribute back to the community with the internal tools we created while working with it.

Because we believe the project can be useful for anyone in the blockchain ecosystem, Convector has joined the Hyperledger Labs initiative. We are really committed to building a community around Convector, which has already surpassed the 27,000 downloads mark, and welcome the input of the Hyperledger community. If you are looking to get involved in an open source project, refer to GitHub

The coordinates for the project are:

About the author
Diego Barahona is the CTO and Architect of WorldSibu, a startup dedicated to creating blockchain tools and platforms for non-blockchain experts and make the technology more accessible to solve business challenges.

Walmart turns to blockchain (and Hyperledger) to take on food traceability and safety

By | 网志, Hyperledger Fabric

In today’s high tech world, the global food supply chain delivers fresh meat, produce and more to us year round. The good news is that this massive supply chain means a consumers have access to a huge diversity of food that is generally safe to eat. Still, occasionally it can make us sick. In 2018 alone, there were 18 outbreaks of foodborne illnesses in the USA, including the E. coli found in romaine lettuce.

For this reason, Walmart has always been interested in enhancing transparency and traceability in the food system. The company has tested many approaches to tackling this challenge before turning its attention to blockchain. Two successful Proof of Concept (POC) projects, one in the U.S. and one in China, solidified Walmart’s commitment to blockchain and Hyperledger Fabric. The company is now leading industry-wide adoption of the technology with a coalition involving some of the most prominent players in the food industry, like Nestle and Unilever.

Walmart’s success working with Hyperledger Fabric and the Hyperledger community to build this large-scale solution and growing industry coalition shows the power of multi-stakeholder, open source approach to blockchain:

  • Since the food traceability system is meant to be used by many parties, including Walmart’s suppliers and even direct competitors, an open and vendor-neutral technology ecosystem was a core requirement from the start.
  • Interoperability with other blockchain systems is also key for a cross-industry solution, making Hyperledger’s collaboration with Ethereum vital for long-term success.
  • The diverse community working together on the development of Hyperledger Fabric meant that solutions were already in the works for many issues the Walmart team identified as they built and scaled their solution.

For details on how Walmart went from a test case with mangoes to tracking more than 25 products from five different suppliers via Hyperledger Fabric, read our case study. It includes the a step-by-step account of Walmart’s rollout, from embracing the general idea of blockchain to selecting a core technology to planning the POC projects and taking the system global with partners. It also featured tips from Frank Yiannas, former Vice President of Food Safety at Walmart, on rolling out an enterprise blockchain project.

(2.14.2019) Bitcoin Exchange Guide: Samsung SDS Reveals Blockchain Tech ‘Nexledger Accelerator’ Passes Hyperledger Fabric Testing

By | Hyperledger Fabric, News

The company, which announced this via a press release, is currently presenting the project at the IBM Think 2019 conference, which is currently happening in San Francisco. The project is being called Nexledger Accelerator and it will use the Hyperledger Fabric technology as a basis for the development of the platform.

 

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