Documentation & Best Practices Flashcards

What is the typical way chaincode should signal a failed business rule to the client?

Answer: Return an error response (e.g., shim.Error or a returned error)

Returning an error produces a clean failed response without crashing the chaincode process.

Which library lets chaincode enforce access control based on the caller's identity and certificate attributes?

Answer: Client Identity (cid) library

The cid library exposes MSP ID, ID, and attributes so chaincode can implement ABAC checks.

What is the best practice for large files such as PDFs that relate to ledger assets?

Answer: Store the file off-chain and keep its hash and a reference on the ledger

Keeping bulky data off-chain preserves performance while the on-chain hash proves integrity.

Frequent MVCC_READ_CONFLICT errors on a single counter key suggest what design fix?

Answer: Avoid hot keys by writing separate delta records using composite keys and aggregating later

Concurrent updates to the same key conflict, so spreading writes across keys avoids version conflicts.

Which logging practice is recommended for chaincode and peers in production?

Answer: Set levels via FABRIC_LOGGING_SPEC and never log sensitive data

Logging levels are configurable, and sensitive data or keys must never appear in logs.

Why should chaincode validate all input arguments?

Answer: Because arguments arrive as untrusted client input

Chaincode must check types, ranges, and formats itself, as clients can send arbitrary data.

What does a good chaincode API document typically describe?

Answer: Function names, parameters, return values, access rules, and error cases

Clear API docs help client developers and auditors use the contract correctly and understand its permissions.