Solution Deployment & Integration Flashcards

A Hyperledger Fabric network needs to add a new organization post-deployment. Which process is required?

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.

Which consensus mechanism is best suited for a permissioned blockchain deployment where throughput is the primary concern and all participants are trusted?

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.

When deploying smart contracts on Ethereum mainnet, what is the primary reason to use a proxy upgrade pattern?

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.

A blockchain solution architect must ensure that event-driven integrations are reliable. Which pattern prevents duplicate processing of blockchain events by downstream systems?

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.

In a Hyperledger Fabric deployment, what is the purpose of the CouchDB state database compared to LevelDB?

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.

A company integrates a blockchain network with an IoT platform. Which security concern is most critical when IoT devices submit transactions?

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.

When designing a blockchain solution that must comply with GDPR's right to erasure, which architectural approach is most appropriate?

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.