The consensus protocol used by Hyperledger Fabric operates in a three-phase process: endorsement, ordering, and validation (commitment). Consensus is finally achieved when the order and results of a block's transactions have met all policy criteria checks that take place during the three-phase life cycle of a transaction, after which consensus peers can query the data.
During the life cycle, the use of endorsement policies dictates which specific members must endorse a certain class of transactions, and system chaincodes ensure that these policies are enforced and upheld. Before transactions are committed, these system chaincodes make sure that an adequate number of endorsements are present, and that they were derived from ...
