Linux Foundation Hyperledger Fabric Certified Practitioner HFCP Exam Practice Test

Answer : D

In Hyperledger Fabric, to enable CouchDB as the state database, the stateDatabase configuration option in the core.yaml file must be changed from goleveldb to CouchDB. This change directs the peer to use CouchDB instead of the default LevelDB for storing the world state, which can then be queried using rich queries and provides additional features like indexing.

Answer : B

In Hyperledger Fabric, client applications can subscribe to receive both chaincode events and block events using the peer's event service. Chaincode events are generated by the chaincode itself, typically based on specific conditions coded within the chaincode operations, and are used to notify applications of specific state changes or significant occurrences. Block events inform about the addition of new blocks to the ledger, which may contain multiple transactions. This dual capability allows client applications to effectively monitor transaction confirmations and specific chaincode outputs in real time, which is critical for applications that rely on up-to-date blockchain data for processing decisions.

Answer : A

When using 'off-line signing' in the Fabric Gateway client API, the cryptographic signature is generated using the message digest. This digest is a hashed representation of the transaction's content, ensuring the integrity and non-repudiation of the transaction as it moves through the Fabric network. This method allows for secure transaction signing without exposing private keys directly on the client-side, aligning with security best practices .

Answer : C

Intercommunication in Hyperledger Fabric regarding how smart contracts update the World State database is primarily achieved by calling other smart contracts, both within the same channel and across different channels. This process allows smart contracts, also known as chaincode, to interact and transact across the network, updating the World State as necessary based on business logic defined in the contracts. This capability is crucial for complex business processes that span multiple contracts and possibly multiple channels. Unlike setting endorsement policies or configuring peer-to-peer options, calling other smart contracts directly facilitates dynamic and direct interaction between business processes, enhancing the modularity and efficiency of the network. Cross-channel communication must be carefully managed within the permissions and policies defined in the network to maintain security and integrity.

Answer : B

Chaincode in Hyperledger Fabric is essentially smart contract software that defines assets and the transaction instructions for modifying these assets on the ledger. Chaincode functions as the business logic layer of the network, where the rules for interacting with the ledger are specified. It is executed on the network peers and is used to encode the policies and constraints associated with asset exchanges or updates within the business network. This setup allows organizations to automate processes and enforce consistency and compliance across transactions.

Answer : C

The Operations Service API hosted on the HTTP server by the peer and the orderer in Hyperledger Fabric does not provide the functionality to set the log level. This API is primarily designed to offer operational insights and controls like retrieving log data, fetching metrics, and performing health checks. The ability to dynamically adjust the log level via this API is not supported, as logging levels are typically configured statically through configuration files or environment variables at the time of node startup. This design helps maintain the integrity and stability of the operational log data.

Answer : B

The last step in the Hyperledger Fabric transaction flow is the commitment of the transaction to the ledger and the subsequent notification to the client application1. Once the transaction has been endorsed and ordered, it is committed to the ledger on all peers. After the transaction is committed, the peers asynchronously notify the client application of the success or failure of the transaction.This ensures that the client application is aware of the outcome and can take appropriate actions based on the result of the transaction1