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

Chaincode-to-chaincode invocation uses stub.InvokeChaincode() to call another deployed chaincode from within chaincode logic.

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

CreateCompositeKey builds structured keys from an object type and attributes, preventing key collisions across different data categories.

Question 3

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

Accepted Answer

peer lifecycle chaincode commit

Answer

The commit command finalizes the chaincode definition on the channel after sufficient organizations have approved it.

Question 4

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

Accepted Answer

stub.SetEvent(name, payload)

Answer

SetEvent allows chaincode to embed a named event with a byte payload in the transaction, which clients can subscribe to via the event service.

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

The collections-config flag points to a JSON file defining private data collections, their membership policies, and data dissemination rules.

CBDH - Certified Blockchain Developer Hyperledger Practice Test