CBDH CBDH Smart Contract Development 3

Question 1

What is a 'chaincode-to-chaincode' invocation in Hyperledger Fabric?

Accepted Answer

One chaincode invoking another chaincode on the same or different channel

Answer

Calling a chaincode from an external client application

Answer

A chaincode calling the ordering service directly

Answer

Upgrading chaincode without downtime

Question 2

In Fabric chaincode, what does `stub.CreateCompositeKey(objectType, attributes)` help achieve?

Accepted Answer

Creates namespace-scoped keys to avoid collisions between different data types

Answer

Generates a unique transaction hash

Answer

Encrypts ledger data

Answer

Links two blocks in the chain

Question 3

Which Fabric 2.x lifecycle command makes an approved chaincode active on a channel?

Accepted Answer

peer lifecycle chaincode commit

Answer

peer lifecycle chaincode install

Answer

peer lifecycle chaincode approveformyorg

Answer

peer lifecycle chaincode package

Question 4

What event mechanism in Fabric chaincode allows clients to listen for transaction-generated notifications?

Accepted Answer

stub.SetEvent(name, payload)

Answer

stub.EmitEvent()

Answer

stub.PublishEvent()

Answer

stub.FireTrigger()

Question 5

What is the purpose of the `--collections-config` flag when committing chaincode in Fabric?

Accepted Answer

Specifies private data collection policies for the chaincode

Answer

Defines which peers can endorse transactions

Answer

Sets the endorsement retry count

Answer

Configures the gossip protocol parameters

Question 6

In Hyperledger Fabric, what does `stub.GetPrivateData(collection, key)` retrieve?

Accepted Answer

Data stored in a private data collection visible only to authorized organizations

Answer

Encrypted public ledger data

Answer

The peer's private TLS certificate

Answer

Off-chain IPFS stored data