CBDH BTA Certified Blockchain Developer - Hyperledger Questions and Answers

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.

Reputation Manager is part of the MSP Membership services provide identity, privacy, and confidentiality to the network. Basic access to the network is determined through the role of the member, who may all have separate legal and/or independent entities. Depending on the network, different authentication schemes are used for assigning identity. For transacting, the participants must obtain identities. The Reputation Manager enables auditors to view transactions pertaining to a participant, providing that each auditor has been granted proper access authority, based on the role of the participants.

/chaincode is the endpoint used for deploying, invoking, and querying chaincode. Which operation you perform is controlled by the body of the request that you send. /registrar allows you to enroll users.

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There are generally two ways to develop business contracts: the first way is to code individual contracts into standalone instances of chaincode; the second way, and probably the more efficient way, is to use chaincode to create decentralized applications that manage the life cycle of one or multiple types of business contracts, and let end users instantiate instances of contracts within these applications

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The application is bootstrapped knowing about a group of peers which are trusted by the application developer/administrator to provide authentic responses to discovery queries. There is the bootstrap of a peer network, during which policies, system chaincodes, and cryptographic materials (certs) are disseminated amongst participants, and the bootstrap of an ordering network. The bootstrap of the ordering network must precede the bootstrap of the peer network, as a peer network is contingent upon the presence of an ordering service. A network need only be “bootstrapped” once.

Hyperledger Fabric is an enterprise permissioned blockchain. It does not have a cryptocurrency nor token. It could be a use case to develop chaincode to create an off chain channel to a cryptocurrency exchange but this would not be efficient.

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Distributed Ledger manages the world state and the transaction log in the blockchain. The world state is defined as the state of all transactions on the Blockchain, where all nodes agree that all blocks on the Blockchain are at the same state. It implements three key attributes. It efficiently calculates the cryptographic hash of the entire dataset of each block. It efficiently transmits a minimal “delta” changes to the dataset, when a peer is out of sync and needs to “catch up”. It minimizes the amount of stored data required for each peer to operate.

Forking" the repository means creating a copy of this repository under your GitHub account. Note that the fork will fork the entire repository including all the branches.

Membership services provide identity, privacy, and confidentiality to the network. Abstraction of an architecture for membership operations.

Decentralized Autonomous Organization (DAO) can be thought of as a corporation run without any human involvement under the control of an incorruptible set of business rules. A DAO can also be seen as the most complex form of a smart contract, where the bylaws of the decentralized organization are embedded into the code of the smart contract, using complex token governance rules.

Explorer can view, invoke, deploy or query blocks, transactions and associated data, network information, chain codes and transaction families, as well as other relevant information stored in the ledger. Powerful, easy-to-use, highly maintainable, open source browser for viewing activity on the underlying blockchain network.

Invoke is called to update or query the ledger in a proposal transaction. 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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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.

Code deploying transaction Code deploying transaction submits, updates or terminates a chaincode. The validating nodes protects the authenticity and integrity of the code and its executing environment. Code invoking transaction Code invoking transaction is an API call to a chaincode function. It is similar to how a URI invokes a servlet in JEE. The displayed function is called upon the instantiation of the chaincode. Each chaincode maintains its own state and a function call is made to trigger chaincode state changes.