leader peer 是peer之間動態選舉選出的

endorsing peer 預設為每個peer都是，安裝chaincode後，實例化設定policy可以有變化

committing peer 預設為每個peer都是

https://medium.com/@kctheservant/transactions-in-hyperledger-fabric-50e068dda8a9
https://stackoverflow.com/questions/52893818/difference-between-endorsing-peer-and-committing-peer-in-hyperledger-fabric/52894994