Difficulty in developing EOS of Ethereum super ledger
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.
EOS is a public chain system at the bottom of blockchain developed by block. One, which is specially designed to support decentralized application of Commerce, and its code is open source
bitcoin is called blockchain 1.0 because it opens up the world of digital cryptocurrency and takes a decisive step from 0 to 1
Ethereum is known as blockchain 2.0, because it provides Turing complete virtual machine that can run smart contracts, bringing unlimited possibilities
and EOS is called blockchain 3.0, why? Two words: performance
The positioning of EOS is the slogan of its home page:English: the most powerful infrastructure for decentralized applications
Chinese: the most powerful decentralized application infrastructure
EOS expects to be an enhanced version of Ethereum, a high-throughput intelligent contract platform
although Ethereum has complete functions, it is limited by its design choice. Due to the block output speed of 15 seconds, the transaction throughput is far from large-scale practical level, which is only about 30 ~ 40tps (transaction / s). EOS, on the other hand, has chosen a different technology route, with the goal of achieving a considerable million TPS, which is quite attractive considering visa's actual processing speed of 1700tps
consensus mechanism of EOS
the reason why the throughput of bitcoin and Ethereum is so low is that they are constrained by the application scenario they envision and the consensus mechanism they choose for the scenario - both of them assume that the environment in which the system runs is totally untrustworthy, so they both adopt the consensus mechanism of proof of work
consensus, as the name suggests, is to reach a unified understanding of something - for blockchain, something refers to the confirmation of the transaction - any node to submit a transaction needs everyone's approval
the pow mechanism currently adopted by bitcoin and Ethereum is the design of the legendary Nakamoto Tsung. Under this mechanism, in order to obtain the bookkeeping right and digital currency reward, miners need to constantly dig for the compliant hash value, and confirm and package the transaction data through the consensus of hash value. POW has no access threshold, and any node has equal rights to participate in bookkeeping. Of course, the probability of winning is related to computing power:
the price of ram is based on Bancor algorithm, that is, it is regulated by market supply and demand: if the supply of ram exceeds the demand, more EOS certificates are needed to buy ram, At this time, more EOS certificates can be obtained by selling ram
memory is a consuming resource, which cannot be redeemed and can only be bought and sold. Take the issue of currency on EOS as an example. At present, the issue of currency requires 20m of memory. An EOS can buy 20KB. According to the current storage price, issuing a currency will consume 1000 EOS. This is the source of EOS memory consumption
Course Overview
this course is for friends who are interested in the development of EOS decentralized application. The course covers the core concepts of EOS DAPP development, the development and deployment of smart contracts, and how the front page interacts with EOS blockchain. Finally, a complete DAPP development based on react and EOS is completed
Chapter 1: enter the world of EOS
to understand the core concepts of EOS, such as positioning and characteristics, consensus mechanism, payment computing model, etc
Chapter 2: Hi EOS
understand the overall framework of EOS node software and the functions of node server, wallet server and command-line tools, learn how to configure and start EOS node server and wallet server, and preliminarily understand the use of command-line tools
Chapter 3: wallet, key and account
understand the three core concepts related to personal identity in EOS: wallet, key and account, and learn how to use command-line tools to create wallet, key and account
Chapter 4: development and interaction of smart contracts
understand the concept and function of smart contracts, learn how to write and compile EOS smart contracts, and learn how to deploy and interact with contracts using command-line tools
understand the persistence mechanism of state in EOS smart contract, and learn to use multi index table to save contract state
Chapter 5: issue your own tokens
learn the principle and implementation mechanism of issuing tokens on EOS, and master how to use command-line tools to issue, transfer and view the balance of tokens through practical operation
Chapter 6: use code to interact with smart contract
understand the principle of interaction between application and EOS blockchain, and learn to use JSON RPC interface and eosjs encapsulation library to access EOS blockchain
Chapter 7: DAPP development of practical notes
comprehensively use EOS knowledge, use react to complete a decentralized application of EOS notes, and learn the complete process from requirement analysis to code implementation
The above course address is as follows: EOS tutorialreviewing the financing of EOS, we not only set many records of ICO, but also a significant milestone in the whole history of open market financing. During the 350 day subscription cycle, 200000 people participated in ICO, accumulating 7.2 million ether coins. According to the market price of the day, the total amount reached US $4.3 billion, which is close to the total IPO amount of Google (US $2.7 billion) and twitter (US $2.1 billion). It is the largest ICO in history so far. It's very worthwhile to make a comprehensive summary. I very much hope that what I write can penetrate the surface of the facts, catch the essence hidden behind, and become a part of historical records
EOS's ICO uses Ethereum's smart contract to complete the automatic subscription and allocation of funds. There is no middleman, and there is no role of investment bank and underwriter of traditional securities listing. This is a primary market. The total number of EOS coins is 1 billion, of which 900 million are distributed to subscribers and 100 million are reserved by block.one. All the funds obtained from the subscription belong to block.one company. Meanwhile, according to the subscription agreement, these funds directly become the profits of the company, and there is no other responsibility and obligation relationship with the subscribers, nor the responsibility and obligation to maintain and develop the EOS software and network. The main network of EOS will be launched by the loosely organized technology forum community, The network operation funds are automatically generated by the code rules, and new EOS tokens are issued to pay to the block procer nodes
in the process of ICO, the secondary market (exchange) is fully opened at the same time. After the completion of the subscription in the primary market, the general financing will enter the secondary market for a period of time. However, the financing cycle is as long as 350 days. The obtained Ethereum EOS token can enter the secondary market for circulation on the same day, resulting in a large number of turnover transactions, The prices of the two markets fluctuated simultaneously
after the end of ICO, the total market value of EOS was US $11 billion, ranking fifth in the list of digital currencies. BCH (US $17 billion), which is closer to fourth place, is more than twice as big as ripple (US $24 billion), which is third place. Compared with the total funding of $4.3 billion, according to the popular view of ICO, it is only three times as much
(1) faster processing speed
first of all, as far as the underlying technology is concerned, EOS claims to be able to process tens of thousands or even millions of transactions per second. What kind of technology is used to achieve this
EOS uses graphene substrate tool to process high frequency data. Let's talk about the graphene underlay tool
graphene is actually a chemical substance. Later, blockchain developers got inspiration from the molecular structure of graphene, believing that the molecular structure of graphene can be applied to the underlying structure of blockchain. So, the graphene we are talking about now basically refers to the blockchain tool group, which is written in C + +
data show that: Based on graphene underlying technology, it can achieve an average confirmation speed of 1.5s, achieve 3300tps data throughput under limited conditions, and can reach millions of TPS, even millisecond level confirmation speed
(2) strong concurrency
in addition, EOS has strong concurrency, which is also related to the underlying architecture of graphene. Concurrency, in short, means that multiple programs can be executed at the same time
EOS is a blockchain infrastructure on which developers can build their own blockchain. Chain to chain does not affect the use of resources between each other
DAPP on EOS is independent of each other and does not affect each other. There will not be a large area of congestion e to the huge resources consumed by indivial application developers on the platform
(3) free
in addition, compared with Ethereum, the most important point of EOS is free. Free is very competitive. In the past, we had to pay fees through bank card transfer, but Alipay and WeChat appeared later. In the early stage, free transfers can be realized through applications such as Alipay and WeChat. It is believed that ring the free time, payment methods such as Alipay and WeChat were graally popularized and accepted by the public.
as we said before, Ethereum transactions need to pay gas, which means that you have to pay a certain Ethereum service charge for each transaction, but it does not need to consume EOS token to conct smart contract and transfer transactions on EOS
there are three main sources of EOS value: bandwidth and journal storage (disk), calculation and calculation backlog (CPU), and state memory (RAM). Resources are allocated according to the number of EOS held by the account, which can attract a larger number of users, so as to meet multiple business scenarios< (4) strong security
compared with Ethereum's smart contract, EOS increases security
we know that there is no legislature in the world of blockchain, so the underlying code is equivalent to the law in real life
however, when it comes to code, bugs cannot be avoided, especially for smart contracts. The harm of bugs is very great, and your digital assets will face great risks
although Ethereum has established various applications and code standards for smart contracts, they can not meet the business needs, and EOS stipulates that the task cannot be fully performed only by code
EOS believes that the source code protocol must be readable. Generally speaking, when a system error occurs, blockchain procers can distinguish what kind of bug the error is based on the readability information, and judge whether the community repair is correct through the readability information< Second, consensus mechanism of EOS: dpos
the consensus mechanism adopted by EOS is "dpos", which means "proof of entrusted rights and interests" in Chinese
Ethereum uses POS (proof of equity). In short, the more money you hold, the more rights you will have in Ethereum
then, EOS proposes dpos on the basis of Ethereum POS (proof of equity), that is, it adds a "Commission" before the proof of equity, to whom? Delegate to the supernode
in the setting of EOS, the super node of EOS should be selected from 100 standby nodes through voting by all users holding money, and finally 21 nodes with accounting rights will be selected
this is a bit similar to the "people's Congress system" in our country. A deputy to the people's Congress represents the interests of a group of people; A super node represents the interests of a group of ordinary nodes. In dpos, there is no need to solve the hash function, but the procer is elected by the holder. Therefore, compared with pow, the efficiency of dpos mechanism in dealing with transactions has been greatly improved
however, there are some defects in dpos. It needs to solve the problem of community voting enthusiasm and rece the number of nodes in order to speed up the voting process, thus aggravating the "centralization" problem
the above advantages enable EOS to rise rapidly, especially in China, the strength of EOS community is very huge
in fact, it's useless for most people to tell them how powerful EOS technology is and how much better it is compared with Ethereum and bitcoin, because it's more about how much dividend you can get from it
three what makes people say EOS is a bubble?
obviously, EOS gives people the hope to get a huge dividend. What hope
with the rapid rise of EOS, people can see the real hope of DAPP application in blockchain. People are eager to hoard enough EOS and get more chips before the large-scale outbreak of DAPP, and then wait for its price to rise tenfold, hundredfold, thousandfold...
however, the answers submitted by EOS are not so satisfactory. In terms of transaction speed, EOS can actually process thousands of transactions per second, which is far from the "million level" described in the publicity
although DAPP has really appeared, it is basically similar to "capital disk" projects or simple games with low operability and poor experience
some time ago, there was a rumor that BM, the founder, was suspected of "abandoning the ship" and running away
BM, speaking in the EOS telegraph group, said: it intends to break the original design, abandon the original consensus mechanism of EOS, and redesign a system that can perfectly solve the problems of centralization, privacy and capacity expansion. This new design will reach tens of millions of TPS...
it's hard to say the future direction of EOS, The reason why the killer DAPP didn't appear can't all be attributed to EOS, which involves the constraints of policy, development team and so on
however, compared with bitcoin and Ethereum, EOS has made some progress and innovation, so we say it is the representative of the blockchain 3.0 era.
The issue of EOS and Ethereum is a hot topic in the whole instry. Some support EOS and some support Ethereum
at present, although the main network of EOS has been online, it still needs to be improved in many places. At present, Ethereum is still in a dominant position
The Ethereum community of God V is not willing to be outdone to develop new technologies to change the shortcomings of Ethereumtherefore, whether Ethereum or EOS will win in the future, or whether a chain will surpass both, there is no definite number
for the questions about EOS and eth, you can see some opinions of the instry leaders (hundreds of celebrities talk about the "EOS" website link), and maybe you can find the answer
Solidness language is a special language for writing and executing smart contracts. It is a contract oriented high-level language running on the basis of Ethereum virtual machine. It was first proposed by the former CTO and co-founder Gavin wood of Ethereum in August 2014. Later, Ethereum developers set up a special team to continuously improve solidness language, At present, it is still under development and optimization. The development storage area on GitHub is HTPs / github.com/thereum/solidness. Here we can learn the most comprehensive details and related documents about the development and iteration process of solidness language. In terms of language style, solid language is deeply influenced by C + +, Python and JavaScript. It is a static programming language, compiled in bytecode mode, so it can run on Ethereum virtual machine. Gavin wood uses the syntax rules of ECMAScript scripting language of JavaScript for reference when developing solid language, which makes it somewhat similar to the existing web development language, but it is quite different. For example, solid language has static type, variable return function and so on. The most important point is that solid language can write contracts with self executing business logic and embedded in smart contracts. Therefore, it is not only one of the basic programming languages of Ethereum, but also the basic programming languages of most other Ethereum based blockchain procts (blockchain 2.0) with smart contracts, It is widely used in the vast majority of blockchain procts, such as hyperledger project, which is developed with soliditv language
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