Purchase, sale and inventory of fabric blockchain

1. Go full stack + blockchain course:
a total of 22 weeks, divided into five stages,
the first stage is 4 weeks, go language foundation and network concurrency, learning the introctory go language,
the second stage is 4 weeks, go language practical web development, crawler development, cryptography, consensus algorithm, realizing lightweight public chain, learning the website and crawler that can develop golang, Achieve lightweight blockchain
stage 3, 4-week Ethereum source code analysis and smart contract DAPP development, master Ethereum core and smart contract development, as well as blockchain,
stage 4, 4-week super ledger, bitcoin EOS, source code analysis and smart contract practice, master super ledger development, cat bitcoin, bifurcated EOS after learning, As well as DAPP development of smart contract
phase 5, 6-week project practice, five enterprise level projects, and one year of blockchain project experience after learning
from the characteristics of the language itself, go is a very efficient language, which highly supports concurrency. Go language itself pays more attention to distributed system, and concurrency processing is relatively good, such as advertising and search, That kind of high concurrency server
go language advantages:
excellent performance, can be directly compiled into machine code, does not rely on other libraries, go is extremely fast. Its performance is similar to Java or C + +
concurrency is supported at the language level, which is the biggest feature of go. It is born to support concurrency, and go is the concurrency supported in gene, which can make full use of multi-core and make it easy to use concurrency
the built-in runtime supports garbage collection, which is one of the features of dynamic language. Although GC is not perfect at present, it is enough to cope with most of the situations we can encounter, especially GC after go1.1
it's easy to learn. The authors of go language all have the gene of C, so go naturally has the gene of C. There are 25 go keywords, but the expressive ability is very strong. It almost supports most of the features you've seen in other languages: inheritance, overloading, object, etc
rich standard libraries, go has built a large number of libraries, especially the network library, which is also my favorite part< As like as two peas, br / > built-in powerful tools, Go language is built with many tools chain, the best should be gofmt tools, automatic formatting code, make team review become so simple, code format is exactly the same, it is very difficult to think differently.
cross platform compilation and fast compilation. Compared with the sluggish compilation speed of Java and C + +, the fast compilation time of go is a major efficiency advantage
disadvantages of go language:
package management: package management of go language is absolutely not perfect. By default, it has no way to make a specific version of the dependency library, nor can it create replicable builds. In contrast, python, node and Ruby all have better package management systems. However, with the right tools, the package management of go language can also perform well
lack of development framework: go language does not have a major framework, such as Ruby's rails framework, Python's Django framework or PHP's laravel. This is a heated discussion in the go language community, because many people think that we should not start with using frameworks. This is true in many cases, but if you just want to build a simple crud API, it's much easier to use Django / djrf, rails laravel, or Phoenix
exception handling: go language can help developers deal with compilation errors by simply returning errors (or call stack) through functions and expected calling codes. Although this method is effective, it is easy to lose the scope of the error, so it is difficult to provide meaningful error information to users. Error package can solve this problem by allowing us to add context and stack trace to return error
another problem is that we may forget to handle errors. Static analysis tools such as errcheck and megacheck can avoid these errors. Although these solutions are very effective, they may not be the right way.

2. Blockchain platform, do you want to see blockchain information? Here is Amway password finance, general chain circle, coin circle, DAPP and other information.

3.

At present, blockchain is not only applied in the financial instry, but also in the following instries, such as banking, payment and cash transaction, network security, academic records and academia, election, network and Internet of things, prediction, right and so on. There are still many areas that need blockchain technology. It can be imagined that the Internet + we mentioned before will become a blockchain + situation in the future

from the demand side, finance, health care, notarization, communication, supply chain, domain name, voting and other fields are beginning to realize the importance of blockchain and try to connect technology with the real society

from the perspective of the investment side, the supply of investment funds for blockchain is graally rising, the investment enthusiasm of venture capital is also rising, and the investment density is increasing. The supply of funds at the supply side is expected to promote the further development of technology

from the perspective of market application, blockchain can become a market tool to help the society rece the cost of the platform and make the intermediary institutions become the past; Blockchain will promote the shift of the focus of the company's existing business model, which is expected to accelerate the development of the company

from the perspective of underlying technology, blockchain is expected to promote the transformation of data recording, data dissemination and data storage management; Blockchain itself is more like an open source protocol at the bottom of the Internet, which will touch or even completely replace the underlying basic protocol of the existing Internet in the near future

from the perspective of social structure, blockchain technology is expected to integrate law and economy and completely subvert the original social supervision mode; Organizational form will change because of it, and blockchain may eventually lead people to a distributed and autonomous society

Where should we start to learn blockchain

first of all, we need to have a comprehensive understanding of the source and cognition of blockchain from a macro perspective. Why do we need to do this? Because if we don't understand, we will have no voice. We don't know how to judge that the next outlet is blockchain. Even if people follow suit, we also need our own learning solution as support. So, what do we need to know? I have listed the contents, For your reference only, if you already know something about it, you can skip this step:

1), basic theory of blockchain

2), basic programming (computer software and hardware foundation, character set and character encoding, HTML5 + CSS3 and other front-end technologies, ECMAScript + BOM + DOM, jQuery, node.js, Ajax and express framework)

3) Go programming language and database operation

4), blockchain 1.0 programming - bitcoin

5), blockchain 2.0 - Ethereum

6), Star Cloud chain and EOS development practice

7), blockchain 3.0 - fabric of super ledger

to you who are still struggling in the tuyere of blockchain: there is a market when there is demand, and the society never lacks excellent technical talents, After a good understanding (you can refer to Qianfeng's blockchain video tutorial), you must be firm and accurate

4. Do you want to learn blockchain development technology or just want to know what blockchain is? If it is the former, you can look at the code of other blockchain projects and learn about it first. If it is the latter, we can pay attention to some good blockchain we media. Blockchain is an emerging instry. There is no ready-made training course. It depends on self exploration and understanding.

5.

Blockchain is a new application mode of distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and other computer technologies. Blockchain is an important concept of bitcoin. It is essentially a decentralized database. At the same time, as the underlying technology of bitcoin, it is a series of data blocks generated by using cryptographic methods. Each data block contains a batch of information about bitcoin network transactions, Used to verify the validity of its information (anti-counterfeiting) and generate the next block

if such technology wants to be put into application, the biggest problem is the "Impossible Triangle problem"

that is, scalability, decentralization and security cannot be achieved at the same time, and only two of them can be achieved

most of the existing public chain projects in the market are difficult to put into use on a large scale

6. This needs to be created with the help of the platform
the hypervessel platform developed by IBM China Research Institute provides a blockchain development and testing environment for blockchain enthusiasts and developers. Through this platform, users can create a multi node blockchain based on hyperledger fabric free of charge and quickly, and play smart contracts on their own chains
of course, decent, a foreign decentralized content sharing platform, can also be created.

7. This is a purely technical thing. I'm too responsible to know how to solve it. It is suggested to consult professional technical personnel or find the official solution
Puyin is a high-quality Tibetan tea asset, which is stored, identified, evaluated and authorized by three parties. It is a standard digital currency issued through encryption and digitization. Puyin implements it in strict accordance with the concept of "white paper on standard digital currency" as its operation guideline. It is also a digital currency based on blockchain technology.

8. See my answer here for the difference between hyperledger fabric and public chain. What is blockchain and how to introce it easily- Hyperledger fabric is the most mature one in the field of alliance chain (private chain). The whole structure of the new version (V1) is like this: first, there are some chain codes on the chain, which can be understood as smart contracts. In short, they are agreed logic. Then a transaction can point to and trigger these contracts, and get an output, which will also be written in the transaction. In addition, the change of the new version compared with the old version is that the nodes of the whole network are divided into two types (client I don't think is the node in the network, because it doesn't participate in consensus). One is called endorser, and the other is peer. In addition, there is a function mole called orderer. Some nodes can act as orderer. The main function of this mole is to sort and package transactions into blocks. The process of the transaction is as follows: 1. First of all, each chain code has a specified approving party. Suppose we consider a chain code for automobile transaction, which has three nodes: A, B and C. for example, the Chain Code stipulates the following logic: before the transaction takes effect, two of a, B and C approve the transaction. 2. At this time, suppose user Xiao Ming wants to buy a car, he generates a transaction request to trigger the chain code for the transaction, and he sends the request to nodes a, B and C for approval. 3. If the request is correct and reliable, nodes a, B and C approve the request. They will directly calculate and generate the result, and then write it as a transaction to feed back to the user (at this time, it is not written into the blockchain, or they call it the ledger). 4. After the user receives the returned transaction, if he confirms that the returned transaction results are consistent, he sends the transaction to the sorting mole, and then the sorting mole sorts all the received transactions according to the time, packs them into blocks, and sends them to all nodes. Note that the sorting mole does not perform any verification on the transaction, that is, no matter whether the transaction they receive is approved enough or not, as long as the format is correct, they are packed into the block. 5. All nodes verify whether each transaction has been approved enough. If so, indicate the valid transaction, otherwise, the invalid transaction. However, no matter what the result is, all transactions will be written into the account book. 6. Finally, if the transaction is successful, the node notifies the user that the transaction has been added to the ledger. Compared with the previous version, V1 has more of these things: 1. The sorting mole is logically disassembled, but in fact nodes can be sorted part-time. 2. With the addition of the approving agent, that is to say, only the approving agent will know the details of your transaction, while other nodes only verify whether they have been approved by the specified approving agent. 3. I don't write about it here, but there is one more thing called channel. Different channels are essentially different independent blockchains. Note: I am not a participant in this project, so the above introction is entirely based on my personal understanding of their documentation. There is very little about the existence of malicious nodes, a core problem of blockchain in their documentation, so I don't know how tolerant they are to malicious nodes. However, from the perspective of the structure itself, it is true that V1 has added a lot of functions, and the structure is very clear and flexible, which can support different application scenarios. However, from a theoretical point of view, there is not much innovation to speak of. The two main problems of blockchain technology, scalability and privacy, have not been solved. Although it claims to solve these two problems, it is actually based on the sacrifice of reliability and safety.

9.

1. Technical language

Python and go are two technical languages mentioned by many companies. Learning needs to be a priority. Moreover, these two languages have great application in the technical direction outside the blockchain. For example, go is used in the background construction of large concurrent systems, and Python is used in the construction of artificial intelligence systems. So learning these two languages is a priority

2. Technical framework

master one or more of bitcoin, Eth and hyperledger. Needless to say, BTC is written in C + +. A large number of currency projects, such as lightcoin, dash, Monroe, zcash, use bitcoin technology for secondary development

eth is the representative of blockchain 2.0, which can build a variety of application classes DAPP on eth network. Now a large number of application blockchain projects are developed using eth platform

hyperledger fabric is a blockchain development platform pushed by IBM, which is mainly used for the development of alliance chain, and is the most popular alliance chain development platform at present

3, algorithm

pow (proof of work), POS (proof of rights and interests algorithm), pbft (Byzantine fault-tolerant algorithm) are all important components of cryptography in blockchain. A full understanding of these algorithms will help you to have a better understanding of cryptography when you participate in the underlying development of blockchain projects

extended data:

blockchain technology is a kind of Distributed Accounting Technology, which is characterized by decentralization, openness and transparency, so that everyone can participate in the establishment of the database, and each established data can not be tampered with, and everyone participates, The problem of trust between strangers is solved

blockchain technology has emerged. It is an accounting technology with the participation of the whole people. The transaction information and data between AB and ab are published to the public and can not be tampered with. As we all know, there is no need for any authoritative Third Party C here. In other words, everyone in the system plays the role of C, which is also called decentralization