Ethereum development framework

1. Ethereum is a new and open blockchain platform, which allows anyone to build and use decentralized applications running through blockchain technology in the platform
just like bitcoin, Ethereum is neither controlled nor owned by anyone - it is an open source project created by many people around the world. Different from bitcoin protocol, Ethereum's design is very flexible and adaptable. It is very easy to create new applications on the Ethereum platform. With the release of homestead, anyone can use the applications on this platform safely
Ethereum is a programmable blockchain. It does not give users a series of preset operations, but allows users to create complex operations according to their own wishes. In this way, it can be used as a platform for many types of decentralized blockchain applications
in a narrow sense, Ethereum refers to a series of protocols that define a decentralized application platform. The core of Ethereum is Ethereum virtual machine (EVM), which can encode any complex algorithm. In computer science terminology, Ethereum is "Turing complete.". Developers can use the existing JavaScript and python as the model of other friendly programming languages to create applications running on the Ethereum simulator.

2.

Ethereum is a new and open blockchain platform, which allows anyone to build and use decentralized applications running through blockchain technology in the platform. Like bitcoin, Ethereum is neither controlled nor owned by anyone - it's an open source project created by many people around the world

Different from bitcoin protocol, Ethereum is very flexible and adaptable. It's very easy to create new applications on the Ethereum platform. Anyone can use the applications on the platform safely

Ethereum is a programmable blockchain. It does not give users a series of preset operations (such as bitcoin trading), but allows users to create complex operations according to their own wishes. In this way, it can be used as a platform for many types of decentralized blockchain applications, including but not limited to cryptocurrency

in a narrow sense, Ethereum refers to a series of protocols that define a decentralized application platform. The core of Ethereum is Ethereum virtual machine (EVM), which can encode any complex algorithm. In computer science terminology, Ethereum is "Turing complete.". Developers can use the existing JavaScript and python as the model of other friendly programming languages to create applications running on the Ethereum simulator

like other blockchains, Ethereum also has a peer-to-peer network protocol. Ethereum blockchain database is maintained and updated by many nodes connected to the network. Each network node runs the Ethereum simulator and executes the same instructions. Therefore, people sometimes call Ethereum "world computer"

this massive parallel operation throughout the Ethernet network is not to make the operation more efficient. In fact, this process makes computing on Ethereum slower and more expensive than on traditional computers. However, each Ethereum node runs Ethereum virtual machine in order to maintain the consistency of the whole blockchain. The consistency of decentralization makes Ethereum have high fault tolerance, zero downtime, and can keep the data stored on the blockchain unchanged and anti censorship

Ethereum platform has no characteristics and value. Like programming languages, it's up to entrepreneurs and developers to decide what to use. However, it is clear that some application types benefit more from the functions of Ethereum than others. Ethereum is especially suitable for those applications that automatically interact directly between points or promote group coordination activities across networks

for example, coordinate the application of point-to-point market, or the automation of complex financial contracts. Bitcoin enables indivials to exchange money without the help of financial institutions, banks or governments. The impact of Ethereum may be more profound

in theory, any complex financial activities or transactions can be automatically and reliably carried out on Ethereum with coding. In addition to financial applications, any application scenario with high requirements for trust, security and persistence, such as asset registration, voting, management and Internet of things, will be affected by Ethereum platform on a large scale

3. 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.

4. At the top of Ethereum is DAPP. It exchanges with the smart contract layer through Web3. JS. All smart contracts run on EVM (Ethereum virtual machine) and use RPC calls. Below EVM and RPC are the four core contents of Ethereum, including: blockchain, consensus algorithm, mining and network layer. Except DAPP, all other parts are in the Ethereum client. The most popular Ethereum client is geth (go Ethereum)

5.

1. about the variability of blockchain

2. eth, if most people agree to modify the chain, that is, variability, then they can modify the blockchain records and contracts

3. etc, blockchain records and contracts can't be modified, that is, they can't be tampered with

4. here are the advantages and disadvantages of the two methods

   The advantage of

5. variability is that people can make timely changes to make the right decisions. Therefore, modifying the specification is more practical than finding loopholes

6. non modifiability means that no matter how smart people are at that time, it is impossible not to make mistakes. Therefore, when problems arise in this scheme, it is best to find and solve the loopholes through the existing legal framework

7. differences in development

8. eth, whether it is intentionally arranged or since its birth, the core decisions of blockchain are made by Ethereum foundation with the participation of the community and most of them are developed by it

9. etc, the decision-making of blockchain is mainly decided by the feedback of three loose, collaborative teams with community participation

10. in any case, anyone can put forward improvement suggestions for the two kinds of blockchains. This is the benefit of open source, and it is also very common. You will find that developers of the two chains communicate with each other through GitHub and reddit. I hope to improve the frequency of communication in order to achieve the common goal

11. about compatibility

12. at present, the two kinds of blockchains are compatible with each other. Contracts or applications written by eth can be applied on etc, and vice versa

13. eth, focusing on ewasm, is committed to providing a platform for more and more developers, while the issue of contract security is secondary, such as viper

14. etc focuses on making developers create more secure contracts, such as viper, iohk research, at the cost of consuming the number of potential developers

15. it's obvious that both chains can accept each other, regardless of whether their wishes are the same or not. My view is that the number of developers is not necessarily related to the quality of the proct

16. about the transaction speed

17. eth, the average is 25 seconds, which will be shortened after upgrading

18. etc, with an average time of 14 seconds, maintained at 10-14 seconds after upgrade, according to ecip-1010 and ecip-1036 protocols

19. about the block capacity

20. eth, with the daily trading volume of eth graally reaching 5 million, the block capacity is graally saturated. This situation is similar to the recent transaction cost of bitcoin. This problem can be solved by expanding the block capacity by increasing the default fuel limit

21. ETC­， At present, there is still a lot of room for block capacity. As more and more people accept etc, the block capacity will also increase, just like eth

22. about community

23. eth, mainly discuss on reddit

24. etc, mainly discuss on slack

25. about monetary policy

26. eth, the planned supply is growing steadily, resulting in an average inflation of 3% in eth blockchain in its life cycle

27. etc, before 2025, inflation will reach 3%, and then the total supply will reach 200 million etc, and then there will be deflation

    As for the regional distribution of trading volume, China accounts for 20%, South Korea 25% and the United States 25%
    In etc, China accounts for 50%, South Korea 25% and the United States 10%
    About securities, at present, investors do not have the option to trade securities. Recently, one of eth's ETFs, trading open-end index funds, was denied by the regulators

28. etc owns etc trading trust, which allows investors to own etc instead of the asset itself

6. Just to learn a little, Heshu software was founded in 2017. It has its own blockchain technology laboratory, focusing on blockchain technology scenarios and application development. For example, the underlying architecture of laikelib blockchain allows users to develop their own independent applications and systems on the chain, which is similar to Ethereum. The advantages of laikelib are small capacity, short block out time of 2 seconds, diversification and independent research and development. The response is still good, and they have set up a technical team composed of experts in the fields of data science, blockchain, cryptography and data analysis. The others are not clear. I hope they can help you and hope to adopt them!

7.

Ethereum is an implementation of blockchain. In Ethereum network, many nodes are connected with each other to form Ethereum network:

Ethereum node software provides two core functions: data storage and contract code execution

in each Ethereum node, complete blockchain data is stored. Ethereum not only saves the transaction data on the chain, but also saves the compiled contract code on the chain

At the same time, a virtual machine is provided to execute the contract code

Ethereum virtual machine

Ethereum blockchain not only stores data and code, but also contains a virtual machine (EVM) in each node to execute contract code - it sounds like a computer operating system

in fact, this is the core difference between Ethereum and bitcoin: the existence of virtual machine has brought blockchain into the era of 2.0 and made blockchain a friendly platform for application developers for the first time

the above content comes from the introction course of Ethereum DAPP development

8. Ethereum architecture consciousness is the 6-tier architecture of regional block chain. They are: data layer, network layer, consensus layer, incentive layer, contract layer and application layer. I personally feel that the best thing to do in Ethereum development is Shengshi Huacai, which is very professional

9. Many projects belong to the new infrastructure category. Just take the procts and solutions launched by lierda group as an example: (information communication, 5g and other infrastructure network construction) lierda lorawan solution has low power consumption, strong anti-interference, low cost and high capacity; Lilda NB IOT solution has wide signal coverage, strong penetration ability, ultra-low power consumption, ultra-high sensitivity, strong anti-interference and low cost Smart city, municipal pipe network) has a mature underground parking energy-saving lighting system to rece lighting costs, system rability and reliability, save maintenance costs, improve management efficiency Artificial intelligence) Intelligent Hotel solutions meet the personalized needs of customers and make the hotel management service more efficient and orderly

10. There are people using ethna. What are you going to do??? Do you need to work on projects? error: Class \&# 39; Ethna_ AppManager\&# 39; not found? ? The reason for the problem is that you don't find ethna in your PHP file_ Appmanager class. Your problem can be solved by using the name of the ethna add app object table?? Among the generated files, the file I generated is called LDL_ User. PHP, add this? require_ once(\& quot; ethna.php\& quot;); Can solve, but the premise is your PHP. INI file include_ Ethna & # 92 has been added to path&# 92; The absolute path of class. This path is the path Apache searches when include and require. In addition, I didn't succeed in connecting Oracle with pear:: dB, but I succeeded in connecting mysql. It seems that Oracle can't run because of the SQL statement automatically generated by ehtna. I'm looking for the reason! Good luck