{"p":"can-20","op":"mint","tick":"can","amt":"1000","rows":[{"df":"qa","content":[{"q":"What are the failure handling principles for blockchain upgrading?","a":"Rollback upgrade: After discovering the failure of the upgrade, timely rollback to the state before the upgrade is required to ensure the normal operation of the blockchain system. The rollback method can be divided into full rollback and partial rollback, which depends on  the degree of impact of the upgrade failure."}]}],"pr":"a751fb8b36366f29d02f515a116834f343876db7333f8e82932bc321905abb7d"}