CBSA Solution Deployment & Integration 3 — Questions and Answers
Question 1: A Hyperledger Fabric network needs to add a new organization post-deployment. Which process is required?
- Restart all existing peer nodes with updated configuration
- Submit a channel configuration update transaction signed by existing organizations (Correct answer)
- Delete the channel and recreate it with the new organization included
- Issue a new genesis block and redistribute to all peers
Correct answer: Submit a channel configuration update transaction signed by existing organizations
Adding an organization requires a channel configuration update transaction that must be signed by the required existing organizations per the modification policy.
Question 2: Which consensus mechanism is best suited for a permissioned blockchain deployment where throughput is the primary concern and all participants are trusted?
- Proof of Work (PoW)
- Proof of Stake (PoS)
- Crash Fault Tolerant (CFT) ordering like Raft (Correct answer)
- Delegated Byzantine Fault Tolerant (dBFT)
Correct answer: Crash Fault Tolerant (CFT) ordering like Raft
CFT ordering services like Raft are optimized for high throughput in permissioned networks where Byzantine behavior (malicious nodes) is not a concern.
Question 3: When deploying smart contracts on Ethereum mainnet, what is the primary reason to use a proxy upgrade pattern?
- To reduce gas costs for every transaction
- To allow contract logic to be updated while preserving the contract address and state (Correct answer)
- To enable multiple contracts to share the same storage slot
- To bypass the EVM's gas limit for complex computations
Correct answer: To allow contract logic to be updated while preserving the contract address and state
The proxy upgrade pattern separates storage from logic, allowing the implementation contract to be swapped while the proxy address and stored data remain unchanged.
Question 4: A blockchain solution architect must ensure that event-driven integrations are reliable. Which pattern prevents duplicate processing of blockchain events by downstream systems?
- Polling the blockchain every second for new blocks
- Implementing idempotency keys and exactly-once delivery guarantees in the event consumer (Correct answer)
- Using WebSockets without acknowledgment logic
- Storing raw block data in a relational database without deduplication
Correct answer: Implementing idempotency keys and exactly-once delivery guarantees in the event consumer
Idempotency keys allow consumers to detect and safely discard duplicate events, ensuring each blockchain event is processed exactly once even if delivered multiple times.
Question 5: In a Hyperledger Fabric deployment, what is the purpose of the CouchDB state database compared to LevelDB?
- CouchDB provides faster key-value lookups than LevelDB
- CouchDB enables rich JSON queries and indexing on world state data, while LevelDB only supports key-value access (Correct answer)
- CouchDB replaces the need for the orderer service
- CouchDB stores the full transaction history whereas LevelDB stores only current state
Correct answer: CouchDB enables rich JSON queries and indexing on world state data, while LevelDB only supports key-value access
CouchDB supports complex JSON document queries and index-based searches on world state, making it suitable for applications that need more than simple key lookups.
Question 6: A company integrates a blockchain network with an IoT platform. Which security concern is most critical when IoT devices submit transactions?
- IoT devices may consume too much network bandwidth
- Compromised IoT device credentials can submit fraudulent transactions to the blockchain (Correct answer)
- IoT devices cannot support JSON payloads
- IoT data is too small to be stored on-chain efficiently
Correct answer: Compromised IoT device credentials can submit fraudulent transactions to the blockchain
If IoT device credentials (private keys) are compromised, an attacker can submit fraudulent transactions under the device's identity, undermining data integrity.
Question 7: When designing a blockchain solution that must comply with GDPR's right to erasure, which architectural approach is most appropriate?
- Store all personal data on-chain and rely on immutability as a compliance argument
- Store personal data off-chain with only a hash or encrypted reference on-chain, enabling off-chain data deletion (Correct answer)
- Encrypt personal data on-chain and discard the decryption key
- Use a permissioned blockchain where administrators can delete blocks
Correct answer: Store personal data off-chain with only a hash or encrypted reference on-chain, enabling off-chain data deletion
Storing personal data off-chain with a hash reference on-chain allows the off-chain data to be deleted for GDPR compliance while the blockchain hash remains without exposing personal information.
CBSA Solution Deployment & Integration 3
A Hyperledger Fabric network needs to add a new organization post-deployment.
Which process is required?