[论文解读] Hyperledger Fabric: A Distributed Operating System for Permissioned Blockchains

Elli Androulaki, Artem Barger+19 more|arXiv (Cornell University)|Jan 30, 2018

Blockchain Technology Applications and Security参考文献 18被引用 506

一句话总结

该论文提出 Hyperledger Fabric，一个模块化、开源的带许可区块链平台，具备新颖的 execute-order-validate 架构、可插拔共识，并支持对通用目的编程语言的支持；通过一个受比特币启发的货币实现，达到高吞吐量和低延迟。

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.

研究动机与目标

• 激发对一种灵活的、带许可的区块链的需求，该区块链将共识与执行解耦。
• 引入一种新颖的架构（execute-order-validate），支持并行背书和可配置的信任模型。
• 描述模块化组件（ ordering service、MSP、gossip、容器化链码）及其如何协同构建可扩展账本。
• 通过一个受比特币启发的加密货币基准测试和性能评估，证明可行性。

提出的方法

• 提出一个三阶段的 execute–order–validate 工作流，用于交易，以实现并行背书和灵活的信任假设。
• 定义一个模块化、可插拔的 ordering service，将共识与执行分离，并支持用于多组织协作的信道。
• 在容器内使用标准语言实现 chaincode（智能合约），以隔离执行并使背书策略可用。
• 使用背书策略来确定哪些对等节点必须背书交易，在排序之前收集输出（读写集）。
• 通过背书策略评估、读写冲突检查以及在各对等节点上的确定性账本更新来验证交易。
• 通过在通用基础设施上对一个受比特币启发的加密货币进行基准测试，衡量吞吐量和延迟来评估性能。

实验结果

研究问题

• RQ1 在支持灵活信任模型的同时，带许可的区块链如何将共识与执行解耦？
• RQ2 一个平台能否以通用语言编写的智能合约在安全、保密和可扩展的方式下执行？
• RQ3 在现实部署中，模块化、可插拔共识的区块链架构的性能特征（吞吐量、延迟、可扩展性）是什么？

主要发现

• Fabric 在常见部署配置中实现端到端吞吐量超过 3500 笔交易/秒。
• Fabric 实现亚秒级延迟。
• 系统在超过 100 个对等节点的规模下表现良好。
• 背书政策允许对交易验证具有灵活且表达性的信任假设。
• 交易在排序前执行，支持并行性并缓解非确定性执行问题。
• 该架构支持信道，使跨组织的账本分区成为可能。