hyperledger

Let's say we have companies A, B, C in a business network. How do these companies each "get a copy of the ledger"? Do they all have to download Hyperledger Fabric, set up a Kube cluster, and connect to it with a card that the original sponsor provides? So, yes, sort-of. There are different ways of kicking things off. You might start with A ,B and C all forming a consortium, installing/deploying the Hyperledger Fabric software and creating and joining a channel that includes A, B and C at the outset. They would all "get a copy of the ledger" for that channel by virtue of the fact that as

I want to write a query in HyperLedger Composer that returns me the count of assets that I have in hyper ledger. I have thousands of records. I don't want to fetch them all and calculate count. Data transfer will be slow I want the query to return the count. Unfortunately there is no count in the composer query language. You would have to create a query to select all the assets then check the length of the results. For example with the Basic Sample Network: query selectAssets { description: "Select all assets" statement: SELECT org.example.basic.SampleAsset } then execute it: let results =

I would like to know how either Fabric or composer can enforce Access Control Logic (ACL). As I read through the documents, ACL is a way to control permission to peers within a channel. When I, as a peer, have a local copy of the ledger, what would prevent me from reading the data that I locally have, although in ACL I am denied to have access? In this case I am talking only about ACL without using the new feature private data collections. I appreciate any help. Thank you very much. Nothing can prevent you from reading the data that you have locally, if you have access to that data. ACL

　　如何建立一个运行在区块链上的世界？ 　　区块链如今还是一个襁褓中的婴儿，在其得到广泛应用、充分发挥潜力之前，有许多事情需要先行解决。比如，我们需要获得政府的认可(这在美国意味着需要逐个州解决政策和监管问题)。 　　对于银行业务、身份识别、记录保存或任何其他需要留存官方记录但如今依然利用老旧政府系统甚至依然靠纸质操作的事项，只有在各种法律和监管障碍扫除后，区块链才能发挥效用。 　　另外，我们需要统一的区块链行业公开标准。目前在此方面努力的最杰出联盟是Hyperledger项目。 　　Hyperledger是一个致力于制定公开、标准化企业级分布式账本框架与代码库以供各行业运用的开源项目。 　　该项目由Linux基金会负责，成员包括科技企业(思科、IBM、因特尔、红帽、三星、威睿等)、大银行(摩根大通、富国银行等)、区块链创业企业(Bloq等)以及许多其他类型组织。 　　该项目最近发布了首个可直接运用于生产的Hyperledger Fabric版本，将作为区块链应用程序的开发基础。 　　微软等重要区块链行业参与者也纷纷进军标准化领域，比如Redmond已发布自有的Coco框架，该框架与现有协议相容，并能为私有区块链添加更强大的治理与数据保密功能。 　　“Linux基金会是保护与孵化开源产品的关键治理层，”Garzik表示。“如今市场上有很多区块链小企业，但我们看到的一个很严重的问题是

I have tried to use docker toolbox to setup Hyperledger V1.0 in my local machines. I according to this document： http://hyperledger-fabric.readthedocs.io/en/latest/asset_setup.html But when I tried to deploy chaincode. $node deploy.js I got an error message： info: Returning a new winston logger with default configurations info: [Chain.js]: Constructed Chain instance: name - fabric-client1, securityEnabled: true, TCert download batch size: 10, network mode: true info: [Peer.js]: Peer.const - url: grpc://localhost:8051 options grpc.ssl_target_name_override=tlsca, grpc.default_authority=tlsca

Watching many examples in Hyperledger Fabric I found two ways to achieved a key: Let's suposse we have two fields visa and type of visa. Visa: "1212323" Type of Visa: "Student Visa" So we can create a key neither: Using CompositeKey function provide by stub key, err := stub.CreateCompositeKey(indexName,[]string{visa, typeVisa}) stub.PutState(key, value) Concatenating the two fields stub.PutState(visa+typeVisa, value) What is the difference between those two approaches? What is the best performance? By using Composite Keys you will have access to extra methods in your chaincode e.g.

fabric 1.4环境搭建总结 1.安装依赖工具 1.1 安装 Git sudo apt update sudo apt install git 1.2 安装Curl sudo apt install curl 1.3 安装docker //查看系统是否已经安装 Docker： docker -- version //未安装，使用如下命令安装最新版本的 Docker： sudo apt install docker . io //安装完之后，查看版本，出现如下字样则安装成功： docker -- version Docker version 18.09 .7 , build 2 d0083d //！！设置成非 root 用户也能执行 docker，需要将普通用户加入 docker 组： sudo usermod - aG docker 你的用户名 （重启生效） 1.4 安装docker-compose //查看系统是否已经安装 docker-compose： docker - compose -- version //未安装，使用如下命令安装 docker-compose 工具： sudo apt install docker - compose //安装完之后，查看版本，出现如下字样则安装成功： docker - compose -- version docker -

Other than the fact that Composer makes deployment and testing of prototype business networks easier and the fact that we don't have to know golang to develop chaincode, what is the difference in the functionalities that these interfaces provide that may lead one to choose one over the other? This article can probably provide you with the answers you need: https://blog.selman.org/2017/07/08/getting-started-with-blockchain-development/ Hyperledger Composer is both an application development framework and set of powerful tools which simplifies and expedites the creation of blockchain

for deploying hyperledger fabric network using composer do i need to deploy composer per orgs (here in this case i'm using 2 orgs on 2 physical machine) or i setup of composer for all orgs is required? anyone have idea on this? Hyperledger Composer can be used against any hyperledger fabric network topology you have defined, you just need to configure connection profiles and build business network cards with these profiles for the actions you want to perform. The best place to understand the connection profile requirements for a multi-organisation setup is in the multi-org tutorial on the