blockchain

问题 Closed . This question needs to be more focused. It is not currently accepting answers. Want to improve this question? Update the question so it focuses on one problem only by editing this post. Closed last year . Yesterday I read about an article on Blockchain and according to it, blockchain are very secured? I am not able to understand how it is secure? How blockchain makes data secure even it is available to normal people? 回答1: @saurabh provided a very good explanation, Its a complex topic

问题 Parity doesn't seem to have any documentation on what it's console output means. At least none that I've found which admittedly doesn't mean a whole lot. Can anyone give me a breakdown of the meaning of the following line? 2018-03-09 00:05:12 UTC Syncing #4896969 61ee…bdad 2 blk/s 508 tx/s 16 Mgas/s 645+ 1 Qed #4897616 17/25 peers 4 MiB chain 135 MiB db 42 MiB queue 5 MiB sync RPC: 0 conn, 0 req/s, 182 µs Thanks. 回答1: Why document when you can just read code? (bleh) 2018-03-09 00:05:12 UTC(1)

问题 I tried to run fabcar example from hyperledger-fabric tutorial https://hyperledger-fabric.readthedocs.io/en/latest/write_first_app.html. when I run ./startFabric.sh I got the error : //Join peer0.org1.example.com to the channel. docker exec -e "CORE_PEER_LOCALMSPID=Org1MSP" -e "CORE_PEER_MSPCONFIGPATH=/etc/hyperledger/msp/users/Admin@org1.example.com/msp" peer0.org1.example.com peer channel join -b mychannel.block 2017-08-06 08:05:59.338 UTC [msp] GetLocalMSP -> DEBU 001 Returning existing

问题 I recently deployed the fabric network using Docker-compose, I was trying to simulate a downed peer. Essentially this is what happens: 4 peers are brought online using docker-compose running a fabric network 1 peer i.e the 4th peer goes down (done via docker stop command) Invoke transactions are sent to the root peer which is verified by querying the peers after sometime (excluding the downed peer). The downed peer is brought back up with docker start. Query transaction run fine on the always

问题 I created a network on hyperledger composer on one physical machine and create cards for admin and user I have some questions: 1) how can I access the same network using 2 different machines(laptops) ? 2) and if it possible to connect this network on hyperledger composer to Android app ? I want to know if these possible or not and how can do that? And I want to know if using hyperledger fabric will be best or go on hyperledger composer? 回答1: It depends on what you mean with "access the

问题 I am actually learning smart contract programming on ethereum and I work with truffle. Right now I am making this tutorial here: https://truffleframework.com/tutorials/building-dapps-for-quorum-private-enterprise-blockchains Where you learn how to create a dapp with quorum. But now I have a problem. I did everything exactly as described, but when I do: truffle migrate I get this error here: $ truffle migrate ⚠️ Important ⚠️ If you're using an HDWalletProvider, it must be Web3 1.0 enabled or

问题 We want to invoke one of the functions from go language chaincode itself. The reason for doing so is that we want to create separate transaction blocks for some logics based on flow. For example, if we have a function named ' transferFund ' and within that, we are reading balances of two persons (let it be a function named ' readBalance '). We want 3 blocks to be created: 1 for ' transferFund ' and 2 for ' readBalance ' 回答1: To invoke another chaincode within your chaincode you can use stub

问题 I need to run Hyperledger-Fabric instances on 4 different machines PC-1 should contain CA and peers of ORG-1 in containers, Pc-2 should contain CA and peers of ORG-2, PC-3 should contain orderer(solo) and PC-4 should Node api Is my approach missing something ? if not how can I achieve this? 回答1: I would recommend that you look at the Ansible driver in Hyperledger Cello project to manage deployment across multiple hosts/vms. In short, you need to establish network visibility across the set of

问题 I installed truffle through npm with the following: sudo npm install -g truffle but when I run truffle list on the console it just gives me bash: truffle: command not found 回答1: Please make sure you have the latest version of npm and node installed. I had the same issue, I updated npm and node to latest version and it worked. npm install -g truffle works. 回答2: I had a similar problem. I ran npm i -g truffle and then when I tried to run truffle init I got an error: zsh: command not found:

问题 I am using IBM bluemix blockchain service to tryout some smart contract logic for my asset sharing demo. Is there anyway to query the asset modified history in hyperledger fabric network. I have checked with documentations for both fabric 0.6 and 1.0 versions, but I can find only the stub.pushState(key,value_json) and stub.getState(key) to interact width the ledger. But using stub.getState(key) , I can fetch only the latest entry of the key, but how can I fetch and display the series of