...by Daniel Szego
"On a long enough timeline we will all become Satoshi Nakamoto.."
Daniel Szego

Thursday, August 1, 2019

Hyperledger Fabric tips and tricks - using time or date in chaincode

If you want to use in your chaincode the exact time or date, it is not a straigtforward thing, because, the different endorsement peers might have different time set and if your commitment information is not the same in all of your commitment peers, the transaction will not be accepted as a valid one. What you can use, is the timestamp of the transaction itself, like with the help of a chaincodeStub.getTxTimestamp() call.

Hyperledger Fabric tips and tricks - chaincode log ID

If you log your chaincode activity, like with the help of a standard logger, it is always a good idea to know for which call was your log message generated. You can use the  getTxId() function call to log the transaction ID for you message. 

Hyperledger Fabric tips and tricks - static variables in chaincode

Do not use static variables in your chaincode in Hyperedger Fabric to store general settings, beacuse if the docker containers are restarted, your setting can be lost. Store instead everything in the ledger, or optionally in the private store.