Which of the following is the identity solution in Hyperledger Fabric?
Answer : D
In Hyperledger Fabric, the identity solution that manages user identities and authenticates participants on the network is facilitated by Membership Service Providers (MSPs). MSPs are crucial for defining the rules by which identities are validated, authenticated, and allowed access to the network. MSPs handle the issuance of certificates and define the roles and permissions associated with participant identities, enabling permissioned interactions on the blockchain. This differs from Hyperledger Fabric CA, which primarily issues and revokes certificates as part of identity management but is used in conjunction with MSPs to provide comprehensive identity solutions within the network.
A smart contract can call other smart contracts both within the same channel and across different channels. Which of the following transactions is inter-contract communication whose functionality is limited?
Answer : D
In Hyperledger Fabric, inter-contract communication is possible both within the same channel and across different channels. However, the functionality to alter the state (using PutState) of a chaincode on a different channel is restricted. This limitation is due to the security and isolation principles of channels in Hyperledger Fabric, where each channel represents a separate ledger and state. Transactions within a channel can read and write data freely, subject to endorsement policies, but writing data to another channel's chaincode directly is not permitted. This prevents unauthorized influence on a separate and potentially isolated business process, ensuring that operations within a channel are controlled and secure.
When building a test network, how many nodes are adequate for an Ordering Service?
When deploying an Orderer environment, variables must be customized or overridden in which artifact?
Answer : D
When deploying an Orderer environment in Hyperledger Fabric, the primary configuration file that must be customized or overridden is orderer.yaml. This file contains the configuration settings specifically for the orderer node, including general ledger type, consensus type, and various operational settings like batching, timeouts, and MSP configurations. Other files like crypto-config.yaml, docker-compose.yaml, and configtx.yaml serve different roles. crypto-config.yaml is used for generating cryptographic material, docker-compose.yaml for defining services, networks, and volumes for containers, and configtx.yaml for channel configuration and consortium definitions. Therefore, orderer.yaml is critical for setting up the orderer's behavior and parameters in the network environment.
Regarding peer lifecycle chaincode, which of the following is the incorrect (unsupported) subcommand for query?
What is the only way to recover from a failed migration from Kafka to Raft?
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 .
Which channel feature allows organizations to run different versions of Hyperledger Fabric on their peer nodes?
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 .