Not all peer nodes are the same. There are different types of peer nodes with different roles in the network:
- Endorser peer
- Anchor peer
- Orderer peer
Peers can be marked as Endorser peer (e.g. Endorsing peer). Upon receiving the “transaction invocation request” from the Client application the Endorser peer.
- Validates the transaction. e.g. Check certificate details and roles of the requester.
- Executes the Chaincode (e.g. Smart Contract) and simulates the outcome of the transaction, but it does not update the ledger.
At the end of the above two tasks, the Endorser may approve to disapprove the transaction.
As only the Endorser node executes the Chaincode (Smart Contract) so there is no necessity to install Chaincode in each and every node of the network which increases the scalability of the network.
Anchor peer or cluster of Anchor peers is configured at the time of Channel configuration.
A reminder: in Hyperledger Fabric you can configure secret channels among the peers and transactions among the peers of that channel are visible only to them.
The Anchor peer receives updates and broadcasts the updates to the other peers in the organization. Anchor peers are discoverable. So any peer marked as Anchor peer can be discovered by the Orderer peer or any other peer.
Orderer peer is considered as the central communication channel for the Hyperledger Fabric network. Orderer peer/node is responsible for consistent Ledger state across the network. Orderer peer creates the block and delivers that to all the peers.
Orderer is built on top of a message-oriented architecture. There are two options are currently available to implement Orderer peer:
- Solo: Suitable for development. Single point failure. Solo should not be used for the production-ready network.
- Kafka: Production-ready Hyperledger Fabric network uses Kafka as the Orderer implementation. Kafka is a messaging software that has high throughput fault tolerant feature.
Blockdaemon will automatically launch a network with an Orderer and a Certificate Authority, both of which are required to get started.
- The launch takes only 3 clicks; Blockdaemon automatically creates the necessary Hyperledger Fabric (HLF) certificates.