Hyperledger Fabric: A Distributed Operating System for Permissioned Blockchains (1801.10228v2)

Abstract: Fabric is a modular and extensible open-source system for deploying and operating permissioned blockchains and one of the Hyperledger projects hosted by the Linux Foundation (www.hyperledger.org). Fabric is the first truly extensible blockchain system for running distributed applications. It supports modular consensus protocols, which allows the system to be tailored to particular use cases and trust models. Fabric is also the first blockchain system that runs distributed applications written in standard, general-purpose programming languages, without systemic dependency on a native cryptocurrency. This stands in sharp contrast to existing blockchain platforms that require "smart-contracts" to be written in domain-specific languages or rely on a cryptocurrency. Fabric realizes the permissioned model using a portable notion of membership, which may be integrated with industry-standard identity management. To support such flexibility, Fabric introduces an entirely novel blockchain design and revamps the way blockchains cope with non-determinism, resource exhaustion, and performance attacks. This paper describes Fabric, its architecture, the rationale behind various design decisions, its most prominent implementation aspects, as well as its distributed application programming model. We further evaluate Fabric by implementing and benchmarking a Bitcoin-inspired digital currency. We show that Fabric achieves end-to-end throughput of more than 3500 transactions per second in certain popular deployment configurations, with sub-second latency, scaling well to over 100 peers.

• The paper introduces a new execute-order-validate paradigm that decouples transaction phases, enhancing scalability and security of permissioned blockchains.
• It presents a modular architecture with pluggable consensus that achieved over 3500 transactions per second with sub-second latency.
• The framework supports standard programming languages and emphasizes robust state management and privacy for diverse enterprise applications.

Hyperledger Fabric: A Distributed Operating System for Permissioned Blockchains

Introduction

The paper "Hyperledger Fabric: A Distributed Operating System for Permissioned Blockchains" presents a pioneering framework for deploying robust and scalable permissioned blockchains. Established under the Linux Foundation's Hyperledger project, Fabric breaks away from traditional order-execute blockchain architectures by introducing a unique execute-order-validate paradigm. This paradigm reforms the system to handle distributed applications written in standard programming languages without the necessity for a cryptocurrency, thereby enhancing accessibility and broadening its applicability.

Architecture and Design Principles

Hyperledger Fabric's architecture is distinctively modular and extensible. It features key components that delineate roles and manage various stages of transaction processing:

1. Execution Phase: Transactions are first simulated by endorsing peers, producing read-write sets (RWS) containing necessary state updates and dependencies.
2. Ordering Phase: Transactions are then ordered using a consensus protocol into a total sequence, forming the basis for consistency across the network. This phase relies on a separate ordering service that ensures the global transaction order.
3. Validation Phase: Peers validate transactions based on the endorsement policy and then perform a read-write conflict check. Verified transactions are subsequently committed to the ledger.

This approach segregates transaction execution, ordering, and validation, mitigating the problems of non-determinism and denial-of-service attacks that typically plague order-execute systems.

Key Innovations

Execute-Order-Validate Paradigm: This novel approach decouples execution from consensus. Transactions are endorsed and executed concurrently by peers before ordering, thereby supporting scalable and efficient transaction processing.

Pluggable Consensus: Fabric supports customizable consensus mechanisms, which can be tailored to specific trust models and deployment requirements. This flexibility contrasts sharply with hard-coded consensus in traditional systems.

State Management: The ledger comprises an immutable blockchain and the current state represented in a versioned key-value store. This division optimizes both performance and accessibility, ensuring efficient state management.

Empirical Results

Fabric's performance evaluation, deploying a Bitcoin-inspired cryptocurrency application (the Fabcoin), demonstrated substantial throughput metrics. It achieved over 3500 transactions per second (tps) with latency under one second in optimized environments. The evaluation underscored:

• Scalability: With additional peers and optimized configurations, Fabric scaled effectively in both local and wide-area network settings.
• Efficiency: The hybrid replication mechanism outperformed traditional order-execute architectures, with significant throughput enhancements, especially when leveraging high-performance consensus protocols.

Implications and Future Directions

The implications of Fabric's design are both theoretical and practical:

• Flexibility in Consensus: The ability to adopt different consensus protocols as plugins makes Fabric adaptable across various industry needs and trust environments.
• Programming Language Support: Fabric's support for general-purpose programming languages facilitates rapid development and integration into existing systems, broadening its accessibility.
• Data Privacy and Security: The modular architecture allows for future enhancements in privacy-preserving technologies, such as zero-knowledge proofs and confidential transactions.

Going forward, optimizing Fabric for even greater scalability and performance remains an area of active research. Furthermore, exploring advanced data models beyond key-value stores and integrating robust privacy mechanisms will be pivotal in enhancing Fabric's application scope.

Conclusion

Hyperledger Fabric embodies an advanced framework for permissioned blockchains, introducing crucial innovations such as the execute-order-validate architecture and pluggable consensus. Its empirical success in handling high throughput with low latency underscores its potential for scalable enterprise applications. Continued research and practical deployments will likely expand Fabric's utility and establish it as a versatile blockchain platform optimized for various industrial domains.