CBDH BTA Certified Blockchain Developer - Hyperledger Fabric Question and Answers

Hyperledger supports the following two types of transactions. Code deploying transaction: A code deploying transaction submits, updates, or terminates a chaincode. Code invoking transaction: A code invoking transaction is an API call to a chaincode function.

Let’s have a closer look at the structure of a block. It consists of three sections Block Header This section comprises three fields, written when a block is created. Block number: An integer starting at 0 (the genesis block), and increased by 1 for every new block appended to the blockchain. Current Block Hash: The hash of all the transactions contained in the current block. Previous Block Hash: A copy of the hash from the previous block in the blockchain.

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This web-based tool allows developers to learn Hyperledger Composer, model out their business network (domain), test that network, and deploy that network to a live instance of a blockchain network. The playground keeps the development model in browser storage, allowing them to be easily uploaded or downloaded. The playground also allows for CRUD (create, read, update, delete) operations to be performed on asset transactions which are created and logged. Composer playground offers a repository of sample business networks that can provide a base for building your own business network.

Nodes use a Peer to Peer protocol not a Client Server. The concept of node is common in all blockchain technologies. The “Node” becomes the communication end point in blockchain technology. Nodes connect to other nodes and that is how a blockchain is formed. Nodes use a type of peer-to-peer protocol for keeping the distributed ledger in sync across the network.

The security module works in conjunction with the membership service module to provide access control service to any data recorded and business logic deployed on a chain network.

An effort to advance cross-industry blockchain technologies. Hyperledger is an open source collaborative effort created to advance cross-industry blockchain technologies. It is a global collaboration, hosted by The Linux Foundation, including leaders in finance, banking, IoT, supply chain, manufacturing and technology.

Hyperledger Sawtooth is a modular platform for building, deploying, and running distributed ledgers. Hyperledger Sawtooth includes a novel consensus algorithm, Proof of Elapsed Time (PoET), which targets large distributed validator populations with minimal resource consumption.

Validity rules (validation) state how the user and the transactions will be validated. This is predetermined by the consensus algorithm.

Hyperledger explorer: Hyperledger explorer, which was originally contributed by IBM, Intel, and DTCC, can 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 other relevant information stored in the ledger.

Chaincode is a decentralized transactional program, running on the validating nodes. As with every chaincode, it implements the Chaincode interface in particular, Init and Invoke functions. Init is called during Instantiate transaction after the chaincode container has been established for the first time, allowing the chaincode to initialize its internal data. Invoke is called to update or query the ledger in a proposal transaction. Updated state variables are not committed to the ledger until the transaction is committed.

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