Category Archives: BlockChain

Hyperledger Fabric – Difference between World State DB & Transaction Logs

distributed ledger world state database transaction logs

This article highlights key differences between World State Database (DB) and Transaction Logs which comprise the Hyperledger Fabric Distributed Ledger. Hyperledger Fabric Distributed Ledger can be said to be a combination of World State Database (DB) and transaction logs. It requires invocation of chaincode (smart contracts) for interacting with distributed ledgers (world state DB and transaction logs). The transactions are stored in the block in the same sequence in which they occured and this is responsibility of ordering service to ensure the ordering sequence of transactions in the block. World State Database Transaction Logs Stores the chain’s state information in form of key-value pairs Stores chain of blocks consisting of transaction details in form of sequence of transactions Stored in database such as LevelDB …

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Posted in BlockChain, Hyperledger. Tagged with , .

Hyperledger Fabric Introduction – Interview Questions / Revision Notes

hyperledger fabric introduction

This article represents practice test and revision notes on Introduction to Hyperledger Fabric. These questions and answers can prove to be very helpful to check your knowledge of Hyperledger Fabric if you are appearing for Hyperledger Fabric interview in near future. Hyperledger Fabric is an open-source framework for building distributed ledger solutions. The unique thing about Hyperledger Fabric is that it supports pluggable implementations of different components such as identity management, consensus algorithm etc. Revision notes on Introduction to Hyperledger Fabric Hyperledger Fabric can be used for creating private and permissionless Blockchain network. Blockchain Participants – Membership Members join Hyperledger Fabric Blockchain network using Membership Service Provider (MSP) service. Hyperledger Fabric allows custom MSP to be plugged. Distributed Ledger – Data and Database Hyperledger Fabric allows ledger data to be stored …

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Hyperledger Fabric Platform Components & Docker Images

hyperledger fabric distributed ledger interview questions

This article represents details on installing / setting up Hyperledger Fabric Platform Components / Binaries  with emphasis on some of the following: Steps for how to install / setup Fabric platform components & docker images Details on platform components which are used for setting up the Fabric network Details on docker images which comprise Hyperledger Fabric network The installation leads to download /pull of docker images which are required to run the Blockchain network using Hyperledger Fabric. Installing Fabric Platform Components & Docker Images The following command can be used to install Platform binaries: In case Docker commands require sudo, the above command looks like following: The script which gets …

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Posted in BlockChain, Hyperledger. Tagged with , .

Hyperledger Tools – When / Why to use them?

Hyperledger Fabric Blockchain with

This article aims to present details on when and why to use which Hyperledger tools. The following are different tools which are referred later in this article: Cello Composer Explorer Quilt This article will be updated on regular basis as newer tools come up. When / Why to use which Hyperledger Tools? The following represents details related with the Hyperledger tools: Hyperledger Tools When and Why to use them? Explorer Hyperledger Explorer is a web application which can be used to view, invoke, deploy or query blocks, transactions and associated data, network information (name, status, list of nodes), chain codes and transaction families, as well as any other relevant information stored in the …

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Posted in BlockChain, Hyperledger, Tools. Tagged with , , .

Hyperledger Interview Questions and Answers – Set 1

Hyperledger Interview Questions

This is the first in series of practice tests / interview questions and answers in relation to Hyperledger products suite for building distributed ledgers / Blockchain business networks. This test focuses on checking your knowledge on different products such as following under hyperledger umbrella. Fabric Sawtooth Iroha Indy Burrow Cello Composer Quilt Explorer Revision Notes – Hyperledger Tools & Frameworks Hyperledger Fabric supports pluggable consensus algorithm (ordering service) and membership service provider Hyperledger Indy can be used to build distributed ledger (Blockchain) related with decentralized digital identities Hyperledger Burrow is used for creating a permissioned Ethereum smart-contract blockchain node that executes smart contract code following the Ethereum specification. Hyperledger Explorer can be used to view, invoke, deploy or query blocks, transactions and associated data, network …

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List of Hyperledger Tools & Frameworks for Blockchain Apps

Hyperledger tools and frameworks

This article represents a list of Hyperledger tools and frameworks for building Blockchain applications and when to use each one of them. Hyperledger Frameworks The following is the list of frameworks that can be used to create blockchain applications based on distributed ledger technology. Hyperledger Fabric Hyperledger Fabric is a blockchain framework implementation. It is one of the foundation framework for developing / building Blockchain applications or solutions with a modular architecture. The most striking feature of Hyperledger Fabric is that it allows components, such as consensus and membership services, to be plug-and-play. At the core of Hyperledger Fabric is container technology which is used to host smart contracts called chaincode that comprise the application logic of the system. The following is the list of cool features of …

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Posted in BlockChain, Hyperledger, Tools. Tagged with , .

15+ Blockchain Jobs Designations for Your Next Blockchain Hire

Blockchain Job Designations

Given that Blockchain has gone mainstream, companies are now hiring blockchain developers at all levels such as following: Blockchain Development Software Engineer Senior Software Engineer Principal Software Engineer Staff Software Engineer Infrastructure Engineer Visual Designer Blockchain Technology Leadership Solution Architect, Application Architect, Lead Architect, Consultant Technology Lead Blockchain Project/Program Management Project Lead Program Manager Practice Head Business Development Business development (VP) Blockchain Job Designations from Below are some of the designations in relation to Blockchain application development whose jobs can be found on Blockchain Developer: Other designations similar to this one are following: Blockchain Software Engineer Blockchain Engineer Blockchain Platform Developer Full-stack Developer (Blockchain) IT Blockchain Engineer Blockchain Developer …

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Blockchain Usecase – Airline Booking and Baggage Tracking

Blockchain usecase for airline booking and baggage tracking

Blockchain is all out there to disrupt different industries requiring greater security (trust), traceability and transparency. Be it supply chain, manufacturing, logistics, real-estate, energy, airline industry etc. Here is another Blockchain use case in relation with Airline booking, baggage tracking, putting travel itinerary on Blockchain. Airlines such as Air New Zealand and Luftansa is exploring Blockchain to enhance / improve security and efficiency of services such as booking (rebooking) and baggage tracking. Blockchain would help connect suppliers such as airlines and hotels directly to sellers, allowing companies to bypass third-party vendors. Both Airline companies such as Air New Zealand and Luftansa has entered into strategic partnership with Winding Tree, a …

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Blockchain Usecase – Air Cargo Industry (Supply-chain)

Blockchain POC flydubai Aircargo Dnata

Blockchain is being aggressively pursued by business owners and technology / business evangelists in order to determine if it would help business grow in addition to bringing competitive edge as a result of technology benefits provided by the Blockchain. Recently, a Blockchain proof-of-concept (POC) is successfully completed by Dnata, a provider of air and travel services in the Middle East. They evaluated the Blockchain potential in Dubai Air Cargo industry. The following company participated in the Blockchain POC: DNata flydubai Cargo IBM Blockchain Technology Benefits As a result of Blockchain POC, following benefits were realized: Elimination of redundant data Enhance visibility and transparency for all stakeholders Business Goal vis-a-vis Business …

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Top 5 Blockchain Technology Online Courses

blockchain technology courses

This is a list of top 5 blockchain technology courses which can be used for training yourself online. My Favorite one is Bitcoin and Cryptocurrency technologies course on from Arvind Narayana, Assistant professor in Princeton University. All these courses are well suited for beginners. Thus, if you are planning for reskilling yourself in Blockchain technologies, go ahead and try one of these courses. Please feel free to suggest one or more courses if I missed to mention them. Blockchain for Business: An Introduction to Hyperledger Technologies A primer to blockchain and distributed ledger technologies. One can learn how to start building permissioned Blockchain applications for their enterprises/business. Following are some of …

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Blockchain Usecase – Freelancer to Benefit Lot More

Blockchain has been revolutionizing different kind of businesses including financial, banking, supply chain management etc. Given the very nature of this Blockchain technology, it is also going to disrupt freelance industry benefiting mostly the freelancers. And, this blockchain network implementation most probably looks to be a public blockchain which can be implemented using platform such as ethereum. Following are some of the platforms which are already working on this idea of using Blockchain for freelancing: Ethlance is a first of its kind platform for connecting freelancers and developers. It has its database running completely on Ethereum public blockchain and front-end source files distributed on IPFS, that means it’s completely …

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Blockchain – Top 6 Bitcoin Blockchain Explorer

The following are some of the Bitcoin blockchain explorer web applications which can be used to search the transactions, addresses, and blocks and determine the relationships between them. Blockchain Info Bitcoin Block Explorer Insight Bitpay BlockCypher      Blocktrail BTC NeoTrackerd Pay attention to some of the following: Height: Height of the block (491105); It implies that 491104 blocks have already been added. Age: Block got created 5 minutes back Transactions: Number of transactions included in the block Size: Size of the block Relayed By:

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Sample Bitcoin Block of Bitcoin Blockchain

sample bitcoin block

This blog represents a sample bitcoin block of a Bitcoin Blockchain. Read greater details from this Oreilly book, Mastering Bitcoin. Pay attention to some of the following: Block file format: The block is represented as a file in JSON format Merkle root: Merkle root represents the hash of the root of merkle tree created as a result of combining hash of children nodes. Leaf of the merkle tree represents the hash of the transaction. It takes up 32 bytes of storage. It forms part of Block header. Time: Timestamp when the block is created. It takes up 4 bytes of storage. Forms part of block header. Difficulty: Represents difficult target and takes …

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Blockchain Developers Interview Questions – Set 2

This page provides quiz (interview questions) for Blockchain Developers. These are questions, primarily, related with Bitcoin Blockchain. Some of the topics covered are following: Merkle tree Block Mining

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Hyperledger Network Certificates & How to Create Them

This blog represents code samples and related concepts on how to create hyperledger network certificates. These certificates will be used by peer nodes in Hyperledger Blockchain network. Crypto Config file for Generating Hyperledger Network Certificates Following is a YAML configuration file which can be used to create certificates for different network entities in the blockchain network. You can save the file with name such as crypto-config.yaml Pay attention to some of the following in above file: There are two high-level entries for organizations managing orderer node and peer nodes. They are OrdererOrgs and PeerOrgs Each org would be defined with attributes such as name, domain, specs, templates, users etc. Specs entry …

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Hyperledger Fabric – Hello World with Blockchain Network

Hyperledger Fabric Hello World is about building your first blockchain network. We will make use of fabric-samples provided by Hyperledger. The first Blockchain network will be built using Docker containers. The first network will result in running containers representing some of the following: Two peer nodes each, representing two different organizations. Thus, one organization will have two peer nodes, one of which is called an anchor node and is used to ensure availability. For two organization, there will be four nodes. One node representing Ordering service Management node to do some of the following activities: Join peers to a channel Deploy and instantiate chain code Drive execution of transactions against deployed …

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Posted in BlockChain, Hyperledger. Tagged with , .