Endorsement in Hyperledger Fabric via service discovery

Hyperledger Fabric (HLF) is a modular and extensible permissioned blockchain platform. The platform's design exhibits principles required by enterprise-grade business applications, such as supply chains, financial transactions, asset management, etc. For that end, HLF introduces several innovations, two of which are smart contracts in general-purpose languages (chaincode in HLF), and flexible endorsement policies, which govern whether a transaction is considered valid. Typical blockchain applications comprise two tiers: The “platform” tier defines the data schema and embedding of business rules by means of chaincode and endorsement policies; the “client-side” tier uses the HLF software development kit (SDK) to implement client application logic. The client side should be aware of the deployment address of chaincode and endorsement policies within the platform. In past releases, this was statically configured into the client side. As of HLF v1.2, a new feature called service discovery, presented in this paper, provides APIs that allow dynamic discovery of the configuration required for the client SDK to interact with the platform. This enables the client to rapidly adapt to changes in the platform, thus improving the reliability of the application layer and making the HLF platform more consumable.