Chaincode Development, Deployment, and Lifecycle Management BDC Practice Questions (Page 6)

Questions 26–30

1. 26application · medium

   A developer is debugging a chaincode that returns incorrect results for a query. The chaincode uses a rich query against CouchDB. The developer wants to see the exact query being executed and the results returned. What is the most effective debugging technique?

   • AAdd a unit test that mocks the query and verifies the expected results.
   • BUse the peer's log to view the query execution plan.
   • CRun the query directly against CouchDB using its REST API.
   • DEnable logging in the chaincode to output the query string and the result set.
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2. 27application · medium

   A chaincode function iterates over all assets in the world state to find those with a specific owner. The function is called frequently and is causing performance issues. Which approach is most likely to improve performance?

   • AUse the GetQueryResult function with a rich query to filter by owner.
   • BUse the GetStateByRange function to retrieve all assets and filter them in the chaincode.
   • CCache the list of assets in the chaincode's global variable and refresh it periodically.
   • DUse a composite key that includes the owner as a component, and use a range query to retrieve assets for a specific owner.
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4. 28foundation · easy

   What is the primary purpose of the ChaincodeStubInterface in Hyperledger Fabric chaincode?

   • ATo handle network communication between peers
   • BTo provide APIs for interacting with the ledger, including get/put state and invoking other chaincodes
   • CTo manage the lifecycle of the chaincode container
   • DTo define the endorsement policy for the chaincode
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5. 29application · medium

   A developer has written a chaincode function that transfers tokens between accounts. They want to write unit tests for this function using the mockstub package. The test should verify that the transfer updates the balances correctly. What is the correct way to set up the test?

   • AUse the real peer's state database to test the chaincode, because mockstub does not support state updates.
   • BUse the peer chaincode invoke command to test the function against a running network.
   • CCall the transfer function directly without initializing the chaincode, because Init is not needed for unit tests.
   • DCreate a mockstub, call the chaincode's Init method, then invoke the transfer function with the appropriate arguments, and check the world state for updated balances.
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6. 30foundation · easy

   In Hyperledger Fabric chaincode, what is the primary method for implementing access control?

   • AEncrypting the chaincode code so only authorized users can execute it
   • BRelying on the endorsement policy to restrict who can invoke the chaincode
   • CChecking the client identity from the transaction context using the stub's GetCreator or GetClientIdentity
   • DUsing the ordering service to filter transactions based on user roles
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