Linux Foundation HFCP Hyperledger Fabric Certified Practitioner Exam Practice Test

Answer : D

In Hyperledger Fabric, if a user submits a transaction with no matching function specified in the smart contract, the unknownTransaction function is invoked by default. This function serves as a catch-all method that can be used to handle cases where the transaction type is not recognized, providing a mechanism to manage or log these occurrences effectively .

Answer : B

In Raft, configuration occurs at two levels: local and channel. The local configuration pertains to node-specific settings such as TLS communication and file storage. The channel configuration, on the other hand, defines the membership and operational parameters of the Raft cluster for a specific channel, including settings like heartbeat frequency and leader timeouts. This dual-level configuration allows for precise control over the behavior of Raft nodes within the Hyperledger Fabric network .

Answer : B

Recovering from a failed migration from Kafka to Raft in Hyperledger Fabric involves restoring the state from a backup. This is necessary because once the ordering service is migrated to Raft and begins committing transactions, reverting to Kafka is not supported without a previous backup. If a migration is botched, and a backup was made at the appropriate point, administrators can roll back to this backup to restore the system to its pre-migration state .

Answer : B

The Fabric Gateway client APIs in Hyperledger Fabric streamline the transaction submission process by combining endorsement, submission, and commitment into a single function. This allows client applications to efficiently manage transaction submissions with a single line of code, specifically through the SubmitTransaction() function. This consolidation simplifies the interaction model for applications, enabling a focus on business logic rather than the underlying blockchain infrastructure details .

Answer : B

Hyperledger Fabric allows different versions of the platform to coexist and interoperate on the same network through the use of channel capabilities. Channel capabilities enable organizations running different versions of Fabric binaries to participate on the same channel. These capabilities govern the features that are used by peer nodes and set the minimum version of the Fabric binaries that can be run by peers joined to the channel. This allows for heterogeneous network environments where different nodes might be running different versions of Fabric software .

Answer : A

For developers looking to iteratively test and develop smart contracts in Hyperledger Fabric without the overhead of the full lifecycle process for each update, the recommended approach is to run the chaincode in development mode. This mode allows developers to test and debug chaincode directly on their machines without having to package, install, approve, and commit changes on the network each time. Development mode simplifies the iterative development process by allowing direct interaction with the chaincode during its development, making it easier to make and test changes quickly and efficiently. This contrasts with other methods that involve manual updates, redeployments, or using a production network, all of which are more time-consuming and complex.

Answer : C

In Hyperledger Fabric, when a transaction that includes the delState('A') function is committed, it results in the removal of the state of the key 'A' from the current state database. However, the history of all transactions that have affected the key 'A' remains intact in the ledger. This operation ensures that while the current state reflects the deletion, the immutability and traceability of the ledger are preserved, allowing for auditability and verification of past states. Options such as setting an empty value to the key or altering the transaction history are not supported, as they would violate the principles of immutability and transparency central to blockchain technology. Therefore, the correct outcome of a delState('A') operation is that the current state of 'A' is deleted, but its transaction history remains accessible in the ledger.