Mixed Deck — All CBDH Topics Flashcards

How is a client's identity accessed within Hyperledger Fabric chaincode?

Answer: Using the ClientIdentity object from the chaincode shim package

Chaincode uses the `ClientIdentity` interface from the `github.com/hyperledger/fabric-chaincode-go/pkg/cid` package to access the invoking client's identity, attributes, and certificates.

Which characteristic BEST describes a successful performance monitoring & optimization culture in Certified Blockchain Developer Hyperledger?

Answer: Continuous learning where all team members actively seek improvement

A culture where all team members actively seek improvement opportunities creates sustainable quality enhancement across the organization.

Which role-based mechanism in Kubernetes controls which users or service accounts can modify blockchain deployments?

Answer: RBAC

Kubernetes RBAC grants permissions to users and service accounts for cluster resources.

What is the purpose of the TLS CA in Hyperledger Fabric?

Answer: To provide certificates for securing communication channels between nodes

The TLS CA issues certificates used to secure transport-layer communications between Fabric components such as peers, orderers, and clients.

Why should results of rich (CouchDB) queries generally not be used to drive state updates in the same transaction?

Answer: They are not re-executed at validation, so phantom reads are not detected

Range queries are re-validated for phantoms, but rich queries are not, so the result set could change before commit.

In Hyperledger Fabric's default chaincode lifecycle, which policy governs whether a chaincode definition can be committed to a channel?

Answer: The LifecycleEndorsement policy

The LifecycleEndorsement policy in the channel application config determines how many organizations must approve a definition before commit.

What is the default lifecycle endorsement policy in Fabric 2.x channels?

Answer: A majority of channel organizations

The default LifecycleEndorsement and Endorsement policies use MAJORITY Endorsement of channel organizations.

When troubleshooting system architecture & design issues in Certified Blockchain Developer Hyperledger, what is the BEST approach?

Answer: Systematic diagnosis starting with the most likely causes and documenting steps

Systematic diagnosis with documentation ensures efficient problem resolution and prevents recurrence by addressing root causes.

What is a 'channel' in Hyperledger Fabric and how does it relate to consensus?

Answer: An isolated ledger and messaging environment where a subset of network members share a consensus context

A channel provides data isolation by maintaining a separate ledger and ordering context, so only channel members participate in consensus for that channel's transactions.

Two Hyperledger Besu nodes start but never peer. Which mismatch is a common cause?

Answer: A different genesis file or network ID, or a bad bootnode enode URL

Besu peers only connect when they share the same network ID and genesis, and bootnodes need a correct enode.

Peers fail with 'x509: certificate has expired or is not yet valid' although certificates were just issued. What should you check first?

Answer: System clock synchronization on the hosts and the certificate validity dates

Clock skew or genuinely expired TLS/MSP certificates produce this exact x509 validation error.

Which metric BEST indicates successful project planning & deployment in Certified Blockchain Developer Hyperledger?

Answer: Achievement of defined key performance indicators and stakeholder satisfaction

KPI achievement and stakeholder satisfaction directly measure whether management activities are producing desired outcomes.

What is the MOST effective way to stay current with developments in security & access control for Certified Blockchain Developer Hyperledger?

Answer: Participating in professional development, industry events, and peer collaboration

A multi-faceted approach including formal development, industry events, and peer collaboration provides the broadest perspective on current developments.

A query could return thousands of results. Which API practice reduces memory pressure in chaincode?

Answer: GetStateByRangeWithPagination with a page size

Paginated queries return bounded result sets and a bookmark for the next page.

Which Hyperledger project is an Ethereum client written in Java that supports public and permissioned networks?

Answer: Hyperledger Besu

Besu is an enterprise-grade Ethereum client supporting EVM smart contracts and consensus like QBFT and IBFT 2.0.

What is the purpose of NodeOUs in an MSP configuration?

Answer: Classifying identities as client, peer, admin, or orderer by the OU in their certificate

NodeOUs let the MSP derive roles from the OU field of an identity's certificate.

What is the MOST important consideration when implementing system architecture & design solutions in Certified Blockchain Developer Hyperledger?

Answer: Alignment with organizational needs and scalability requirements

Technology solutions must align with organizational needs and scale appropriately to deliver value both now and in the future.

What does GetHistoryForKey return?

Answer: The sequence of values, transaction IDs and delete flags for a key over time

The history database tracks each committed change to a key, including TxId and delete markers.

Which service delivers committed blocks and filtered blocks to client applications in Fabric?

Answer: Deliver service on peers

Peers expose a Deliver API used by clients to stream blocks and events.

Which setting makes peers require TLS client certificates from connecting clients?

Answer: tls.clientAuthRequired=true

Setting clientAuthRequired enables mutual TLS.