Blockchain Developer

Posted by Tutorials Diary on December 21st, 2020

What is Enterprise Blockchain

Blockchain which is used for Enterprises known as Enterprise Blockchain. Hyperledger is one of the examples where we use fabric, Sawtooth etc to develop enterprise specific applications.

Enterprise blockchain are also known as permissioned blockchain as participants are known to each other and blockchain is not open to everyone.

Enterprise Blockchain is different from Public Blockchain in many aspects as this is mainly designed fro Enterprises.

 Difference between Enterprise and Public Blockchain or why we need Enterprise Blockchain

Features of Enterprise Blockchain

Blockchain is Immutable

Cost saving by eliminating middleman

High availability

High Transparency

Automation of manual processes

Increase trust

Examples of Enterprise Blockchain

Hyperledger Fabric

Corda

Qurom

 What is Hyperledger?

Hyperledger was initiated by Linux foundation as a base project to create blockchain based applications.

Hyperledger is one of most popular software for enterprise blockchain

What is Hyperledger Umbrella Project?

What is Hyperledger Fabric?

Hyperledger Fabric is a software that helps developers to develop enterprise blockchain solutions.

Features of Hyperledger Fabric

·        It features a plug-and-play consensus. 

·        Support different programming languages for chaincode development

·        Faster transaction rate.

·        It offers a flexible approach to data privacy – it performs data isolation via ‘channels,’ data sharing on a need-to-know basis by leveraging private data ‘collections.’ 

·        Offer different SDK’s

What is channel in Hyperledger Fabric?

Channel is one of very important feature of Hyperledger fabric that helps participants to have secrets transactions without letting the whole network know.

This feature is not available in Public blockchain as each transaction is seen by anyone but in Fabric you can restrict who can see & do what.

 Can we have multiple channel in Fabric Network?

Yes, there can be n number of channels in a network, but overuse of channel is also not recommended.

 What is MSP (Membership service Provider)?

1. Contains list of parties/actors involved in Blockchain network

2. Provide identity to each participant

What is Fabric CA?

It is a certificate authority component which can integrate existing registry like LDAP

MSP leverages fabric CA component

 What is ACL (Access Control List)?

By using Access Control List (ACL)

1. Handle permission for parties involved 

2. Handle permission at channel level also

What is Committing Node?

No, not all nodes keep copy of ledger, only few nodes keep that and that nodes are known as Committing nodes.

 What is Endorsing Node?

No, not all nodes execute chaincode , only few nodes do that and that nodes are known as endorsing nodes

What is Ordering service?

Sequence of transactions is very important in Blockchain and that is maintained by Ordering node.

 What is State Database?

 List down the high level steps involved in Hyperledger fabric Transaction

Step 1: Client start the transaction

Step 2: Validation of client and transaction

Step 3: Endorsing peer simulate the transaction and send response back to client

Step 4: Verification of responses

Step 5: Broadcast the transaction to Ordering service

Step 6: Order the transaction and put to block

Step 7: Block validation by peers

Step 8: Add block to ledger

 What is the default consensus algorithm used in Fabric?

It use PBFT where we look for 2/3rd Majority to proceed further.

In which scenario the transaction not added to Block?

·        When consensus is not reached

·        Transaction is invalid

Can any client connect to network and send the transaction?            

No, only authorized clients can send the transactions. In the validation step, client identity is checked if that does not match then transaction is nor processed fur

List down the prerequisites steps for Hyperledger Fabric setup        

Operating System: Ubuntu Linux 14.04/16.04 (64 bit)

git & curl: latest version

go version: 1.13.x

Gradle

Nodejs: 8.9 and higher with the exception of 9

libtool: latest version

Docker Engine: 17.06.2 or higher

Docker Compose: 1.14 or higher

Python: 2.7.x

 Why you need Docker engine for Hyperledger fabric?   

Hyperledger fabric uses different docker containers, like ordering service has its own docker container, chaincode has its own etc.

 Why you need to install go language? 

Go language is used to develop the smart contracts (chaincode) in Hyperledger Fabric.

 Why you need Gradle?

Gradle is build automation tool needed when you use Java as programming language for chaincode development.

Blockchain developer is one of the fastest-growing sectors. Companies are looking for blockchain developers to make new implementations, advance their current systems, and get ahead in the industry. 

blockchain interview questions have a different level of difficulty attached to it. To ensure that you can go through them without any issue, we will group similar questions.