A CorDapp has been live for several months, and the team needs to add a new field to an existing state. The new field is required for future transactions, but existing states must remain valid. What is the correct upgrade strategy?

Add the new field to the state class and use a default value for existing states

Use a new contract version and keep the old state class unchanged

Create a new state class with a new contract and migrate existing states to the new state

Modify the existing state class and contract, and redeploy the JAR to all nodes

A developer is writing an integration test for a CorDapp that involves two nodes. The test must verify that a state created by one node is visible to the other node. Which testing framework feature should be used?

Use MockNetwork and run a flow that creates the state, then query the other node's vault

Use a unit test that directly calls the contract's verify method

Use the node driver to start a real network and manually check the vault

Use a single node and inspect its vault after running the flow

A developer is writing a flow that must handle a large number of inputs and outputs. The flow is expected to be long-running and may be interrupted. What is the best approach to ensure the flow can resume?

Use a single large transaction to process all inputs and outputs at once

Use a flow that does not checkpoint and instead restarts from the beginning if interrupted

Use checkpoints to save the flow's state at key points

Use a sub-flow to process each input and output individually

A developer is writing a unit test for a flow that creates a new state. The test needs to verify that the transaction is signed by both parties and that the state is recorded. Which testing approach should be used?

Use a simple JUnit test that calls the flow's call method directly

Use the Corda test framework to verify the contract's verify method only

Use the Driver and MockNetwork to run the flow and inspect the ledger

Use the node driver to start a real Corda network and test the flow

EC-CouncilBlockchain Developer Certification

Domain 8Objective 4

CorDapp Development and Lifecycle BDC Practice Questions (Page 2)

Part of the Enterprise Blockchain Platforms domain, which makes up ~10% of our current practice bank.

38questions here

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Questions 6–10

6application · medium
A CorDapp has been live for several months, and the team needs to add a new field to an existing state. The new field is required for future transactions, but existing states must remain valid. What is the correct upgrade strategy?
Select an answer first
7foundation · easy
Which CorDapp component is used to automate the process of proposing, signing, and recording a transaction on the ledger?
Select an answer first
8application · medium
A developer is writing an integration test for a CorDapp that involves two nodes. The test must verify that a state created by one node is visible to the other node. Which testing framework feature should be used?
Select an answer first
9expert · hard
A developer is writing a flow that must handle a large number of inputs and outputs. The flow is expected to be long-running and may be interrupted. What is the best approach to ensure the flow can resume?
Select an answer first
10application · medium
A developer is writing a unit test for a flow that creates a new state. The test needs to verify that the transaction is signed by both parties and that the state is recorded. Which testing approach should be used?
Select an answer first

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