Blockchain區塊鏈架構設計之六：Fabric 1.0賬本設計（1）

Fabric是一種開源區塊鏈實現，部署環境可以是私有伺服器，也可以直接部署在公有雲上，部署方式可傳統可docker化，共識演算法插件化，支持用Go和JavaScript開發智能合約，尤以企業級的安全機制和CA機製為特色。Fabric之於區塊鏈，很可能正如Hadoop之於大數據。經過在Hyperledger超級賬本將近一年的孵化，社區計劃在3月發布1.0的預覽版本。本文將重點對Fabric 1.0（alpha&beta）的重點架構升級 - 1）賬本 2）資料庫 整體的設計思路進行一些介紹。

一、設計目標

二、賬本的組成

最大的不同是增加了對基於文件系統的區塊鏈賬本的支持，可以更好地支持不可篡改的特性。

三、完整交易步驟

四、交易流程圖

五、傳遞的消息結構

六、使用智能合約數據的方式

依託可插拔特性引入的CouchDB資料庫，提供了基於JSON數據格式的多種數據查詢能力，豐富了合約代碼可以實現的功能。

未完待續，下一部分更新資料庫的具體改變。

最後，為了實現Fabric V1.0 的設計目標，依然有大量Todo工作需要廣大技術人士支持，感興趣的可關注如下JIRA未關閉問題，對代碼進行開源貢獻。

Network setup and administration

• FAB-359 Bootstrap a blockchain network with orderers and peers

• FAB-686 Create channels among subset of network peers for private communications and ledgers

• FAB-290 Optionally configure Gossip protocol for high availability of peer node

• FAB-678 Ability to deploy fabric from dockerhub

Fabric CA and Security

• FAB-361 Provide a Fabric certificate authority

• FAB-266 Use transaction certificates with Fabric CA that are anonymous and unlinkable

• FAB-1219 Support access control policies for chaincode (creation, termination, invocation - in terms of chaincode library)

• FAB-1329 Support access control policies for channels (create, read, write)

• FAB-353 Pluggable interface for crypto algorithms to accommodate alternative implementations

• FAB-1321 Pluggable interface for an identity manager to accommodate alternative implementation

• FAB-1978 Multiple roots of trust

• FAB-1986 Ability to use an existing (commercial) CA

Ordering service

• FAB-1971 Serialize concurrent chain code transactions into a block

• FAB-1972 Provide an ordering service that ensures transactions are well formed with correct signatures

SDK - Java, NodeJS

• FAB-51 Common API design for SDKs implemented in all languages

• FAB-1967 Event notifications form peer on transaction commits

• FAB-1968 Ability to deploy, invoke, and query Chaincode on pre-existing channels

Chaincode

• FAB-1973 Ability to write Smart Contracts (Chaincode) in Java

• FAB-1974 Ability to write Smart Contracts (Chaincode) in Go

• FAB-1975 Ability to create endorsement policies for a chaincode during deployment

Ledger

• FAB-758 Ledger support for endorsement/validation/commit model, including file-based block storage

• FAB-788 Ledger state based on embedded LevelDB (RocksDB replacement)

• FAB-199 Ledger option for external/queryable state database (CouchDB beta)

• FAB-1257 Chaincode APIs for JSON-based data structures (Replace Table-based APIs)

• FAB-196 Ledger APIs to query Blocks/Transactions, including rich query and history of key values

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