Storage system based on blockchain Technology
From the perspective of technology and architecture, I will tell you my understanding of blockchain in common language
what is blockchain? In a word, blockchain is a storage system. To be more specific, blockchain is a distributed storage system without an administrator and each node has all the data
What are the common storage systems like
first, how to ensure high availability
the common storage system usually uses "rendancy" to solve the problem of high availability. As shown in the figure above, if the data can be copied into several copies and rendant to multiple places, high availability can be guaranteed. The data in one place is hung, and there is data in other places. For example, the master-slave cluster of MySQL is the same principle, and the raid of disk is also the same principle
two points need to be emphasized in this place are: data rendancy often leads to consistency problems
1. For example, in the master-slave cluster of MySQL, there is actually a delay in reading and writing, which means there is a inconsistency in reading and writing in a short period of time. This is a side effect of data rendancy
The second point is that data rendancy often reces the efficiency of writing, because data synchronization also consumes resources. If you add two slave libraries, the write efficiency will be affected. The common storage system is to use rendancy to ensure the high availability of dataso the second question, ordinary storage system, can write more
the answer is yes, for example, take this graph as an example:
in fact, MySQL can do a master-slave synchronization of al masters, master-slave synchronization of al masters, two nodes can be written at the same time. If you want to do a multi room multi live data center, in fact, multi room multi live data synchronization. What we should emphasize here is that multi-point writing often leads to the consistency problem of writing conflicts. Take MySQL as an example, suppose that the attribute of a table is self incrementing ID, then the data in the database is 1234 now. If one of the nodes writes and inserts a piece of data, it may become 5, and then these 5 pieces of data are synchronized to another master node, Before synchronization, if another write node inserts a piece of data, a piece of data with self incrementing ID of 5 will be generated. Then, after the generation, synchronize to another node, and the synchronized data will conflict with the two local 5's after it arrives, which will lead to synchronization failure and write consistency conflict. This problem will occur in the case of multi-point writing
how to ensure consistency in multi-point writing
the reform "Swan class" gives you more technical work
From the perspective of technology and architecture, I will tell you my understanding of blockchain in common language
what is blockchain? In a word, blockchain is a storage system. To be more specific, blockchain is a distributed storage system without an administrator and each node has all the data
What are the common storage systems like
as shown in the figure above, the bottom is data, and the top can write data. A space to store data, a software to manage data, provide an interface to write data, this is the storage system. For example, MySQL is the most common storage system
What are the problems of ordinary storage system? There are at least two common problems
the first is the problem of non high availability. There is a dangerous place for data. In technical terms, data is not highly available
The second problem is that there is only one write point. In technical terms, it is a single point of control
How do ordinary storage systems usually solve these two problems
in fact, MySQL can do a master-slave synchronization of al master, master-slave synchronization of al master, two nodes can be written at the same time. If you want to do a multi room multi live data center, in fact, multi room multi live data synchronization. What we should emphasize here is that multi-point writing often leads to the consistency problem of writing conflicts. Take MySQL as an example, suppose that the attribute of a table is self incrementing ID, then the data in the database is 1234 now. If one of the nodes writes and inserts a piece of data, it may become 5, and then these 5 pieces of data are synchronized to another master node, Before synchronization, if another write node inserts a piece of data, a piece of data with self incrementing ID of 5 will be generated. Then, after the generation, synchronize to another node, and the synchronized data will conflict with the two local 5's after it arrives, which will lead to synchronization failure and write consistency conflict. This problem will occur in the case of multi-point writing
how to ensure consistency in multi-point writing
the reform "Swan class" gives you more technical work
The hottest things this year are "bitcoin", "Ethereum" and all kinds of cryptocurrencies, so hot that even aunts and uncles are about to start talking about them. It is no exaggeration to say that 2017 is the first year of the development of cryptocurrency and blockchain technology
as the underlying technology behind bitcoin, the concept of blockchain has only been mentioned in the past two or three years, although as early as 2009, "Nakamoto Tsung" released bitcoin. After this wave of digital currency boom, the concept of blockchain technology has really entered the eyes of all walks of life. I'm afraid it's too early to mention the wide application of blockchain technology, which is still in a very early stage of development. However, e to the arrival of the boom, many technicians and teams have contributed their efforts to build some blockchain concept projects“ Needless to say, as the first application of blockchain technology, bitcoin of "Zhongben cong" has realized the function of distributed ledger, which can realize the first decentralized value transmission of human beings. It can be said that it is "blockchain 1.0". Then Ethereum invented the smart contract, which extended the function of blockchain technology to build applications. It is well deserved to be defined as "blockchain 2.0". However, the blockchain concept projects that came out later did not realize this leap forward role, but only improved to a certain extent at the application level, so they can not be called "blockchain 3.0"
so what is "blockchain 3.0"? Maybe bitcoin OS is the answer: an operation system that is completely based on blockchain technology and follows the concept of blockchain technology. In the 1980s, before Microsoft released the windows operating system, personal computers and Internet technology were still in a non systematic state and could not be popularized. After the release, personal computers were allowed to enter ordinary people's homes, making PC and Internet universal application procts. Recently, bitcoin OS team announced the implementation of the bifurcations of bitcoin and Ethereum on Christmas day, so as to officially publish the plan of developing blockchain OS
anyone who knows a little bit about blockchain technology knows that bitcoin solves the problem of account book, while Ethereum is a smart contract to realize application expansion. Later, a team will launch a distributed storage project. But these systems with only a single functional mole are not "operating systems". The traditional definition of operating system is a huge management and control program, which includes five management functions: process and processor management, job management, storage management, device management and file management. In fact, the OS based on blockchain does not need to change all the five functional blocks into distributed ones, as long as the parts related to the external transmission of value and information can be decentralized and distributed. Therefore, the blockchain operating system should have at least three functions of "account system management, computing resource management and storage resource management", which can realize distributed ledger, edge computing and edge storage. Although it is still too early to define the instry standard in this way, bitcoin OS team is committed to realizing the blockchain OS possessed by these three functional blocks first, and then improving it through iteration
according to the bitcoin OS team, the name "bitcoin OS" is actually "blockchain OS", which is named after "bitcoin", which is also a tribute to the inventor "Satoshi Nakamoto". At present, from the technical details given by the bitcoin OS team, we may be able to see some aspects of this "blockchain 3.0" project
firstly, the management function of the account book system supports locating the ownership of resources according to the account ID, such as the private key; Computing resource management can obtain corresponding computing resources according to the demand, support edge computing, and share distributed computing power. In addition, storage resource management can use storage resources according to the demand, and support edge storage. Compared with bitcoin OS, Ethereum only supports account system and smart contract, which can not meet the distribution of distributed computing tasks. Ethereum only supports the fair execution of contract code, let alone the management of storage resources. So Ethereum is only a custom calculator
in addition, it is worth mentioning that bitcoin OS self customized enhanced smart contract. It supports two modes, which are more flexible and efficient
1. Central computing mode: the outgoing node is responsible for executing the smart contract, and both the incoming parameters and the output results support sipfs to be stored in the storage node
Distributed computing mode: ordinary nodes can claim computing tasks, input parameters and output results support sipfs storage to storage nodesfinally, we also need to mention the built-in sipfs super interstellar file system of bitcoin OS. Sipfs can realize the decentralized storage of technical input parameters and output parameters. At the same time, the file has a life cycle, and the DNA description of the file descriptor is recorded on the blockchain. The file descriptor of sipfs does not exist on the blockchain, but it will be stored in a separate file descriptor data file. After the end of the file life cycle, the blockchain will automatically delete the file descriptor, Realize the intelligent slimming of blockchain
"blockchain 3.0" is worth looking forward to, and bitcoin OS team, as the vanguard, is worth paying attention to and encouraging. We are looking forward to the real blockchain operating system
first, data security: blockchain makes data flow "at ease"
with its trustworthiness, security and non tamperability, blockchain liberates more data. A typical case is used to illustrate how blockchain promotes the generation of big data for gene sequencing. Blockchain sequencing can use the private key to limit access rights, so as to avoid the legal restrictions on indivial access to gene data, and use distributed computing resources to complete the sequencing service at low cost. The security of blockchain makes sequencing an instrialized solution, realizing global scale sequencing, thus promoting the massive growth of data< Second, data open sharing: blockchain guarantees data privacy
the government has a large number of high-density and high-value data, such as medical data, population data, etc. The opening of government data is the general trend, which will have an inestimable impetus to the development of the whole economy and society. However, the main difficulty and challenge of data opening is how to open data while protecting personal privacy. Data desensitization technology based on blockchain can ensure data privacy and provide a solution for data opening under privacy protection. Data desensitization technology mainly uses hash processing and other encryption algorithms. For example, enigma based on blockchain technology can protect the privacy of data and eliminate information security problems in data sharing by computing data without accessing the original data. For example, employees of a company can safely open the path to access their salary information and jointly calculate the average salary within the group. Each participant can know his or her relative position in the group, but he or she knows nothing about the salaries of other members< The schematic diagram of data hash desensitization processing
3. Data storage: blockchain is a kind of database storage technology that can not be tampered with, full history, strong endorsement
blockchain technology, through all nodes in the network participate in the calculation together, and verify the authenticity of their information to achieve the consensus of the whole network, it can be said that blockchain technology is a specific database technology. So far, our big data is still in a very basic stage. The data based on the consensus of the whole network and the reliable blockchain data are tamperable and historical, which makes the quality of the data gain unprecedented strong trust endorsement, and also makes the development of the database enter a new era< Data analysis: blockchain ensures data security
data analysis is the core of realizing data value. In data analysis, how to effectively protect personal privacy and prevent core data leakage has become the primary consideration. For example, with the application of fingerprint data analysis and the popularization of genetic data detection and analysis, more and more people worry that once personal health data is leaked, it may lead to serious consequences. Blockchain technology can prevent this kind of situation through multi signature private key, encryption technology and secure multi-party computing technology. When the data is hashed and placed on the blockchain, the use of digital signature technology can enable those authorized people to access the data. The private key not only ensures the privacy of data, but also can be shared with authorized research institutions. The data is stored on the decentralized blockchain and analyzed without accessing the original data. It can not only protect the privacy of the data, but also provide it to the global scientific research institutions and doctors for sharing. As the basic health database of all mankind, it will bring great convenience to solve the sudden and difficult diseases in the future
v. data circulation: blockchain protects the rights and interests related to data
for valuable data assets of indivials or institutions, blockchain can be used to register them. Transaction records are recognized, transparent and traceable throughout the network, making clear the source, ownership, use right and circulation path of big data assets, which is of great value to data asset transaction
on the one hand, blockchain can break the threat of intermediary ing data, which is concive to the establishment of a trusted data asset trading environment. Data is a very special commodity, which is essentially different from ordinary commodities. It is mainly characterized by unclear ownership and "being owned after seeing and ing", which also determines that the traditional commodity intermediary transaction method can not meet the needs of data sharing, exchange and transaction. Because the intermediary center has the conditions and the ability to and save all the flowing data, it is extremely unfair to the data procers. This threat can not be eliminated only by commitment, and the existence of this threat has become a huge obstacle to the flow of data. Based on the decentralized blockchain, it can break the threat of ing data in the intermediary center and protect the legitimate rights and interests of data owners
on the other hand, blockchain provides a traceable path, which can effectively solve the problem of data right confirmation. Through multiple nodes participating in the calculation in the network, blockchain can participate in the calculation and recording of data together, and verify the effectiveness of their information. It can not only carry out information anti-counterfeiting, but also provide a traceable path. The transaction information of each block is strung together to form a complete detailed list of transactions. The context of each transaction is very clear and transparent. In addition, when people have doubts about the "value" of a block, they can easily trace back the historical transaction records, and then judge whether the value is correct, and identify whether the value has been tampered or recorded incorrectly
with the protection of blockchain, big data will naturally become more active
the tokens of crowdfunding projects on coin Ying China platform are all developed based on blockchain technology, and relevant information will be recorded on the blockchain.
it's normal for the stock market to fluctuate by 30-40% a year, and the fluctuation of exchange rate by more than 20% is very large. However, if the leverage ratio is included, the profit and loss fluctuation of foreign exchange futures may be much higher than that of stock market futures, but these are just numbers games< In the end, derivatives only provide a mathematical calculation.
to practice guitar: most of them are basswood panels, some even basswood back panels, which are less than 300 yuan, also known as firesticks (because they are made of the same material as firewood, and the intonation is poor)
entry guitar: most of them are spruce panels, rosewood finger boards, and the back panels are not necessarily. The price is about 1000 yuan, and most of them are 500 yuan or 600 yuan, About 1000 yuan, there are also some elementary Miandan Qin
medium Guitar: most of them are spruce panel, rosewood fingerboard, back side panel, mahogany and fire rosewood. Generally, they are middle end single piano of various series, and some of them are full single (very few), with the price around 3000
high end: all single guitars and spruce veneers are the most popular. The price is four or five thousand or more. There is no upper limit. There are tens of thousands of them, but most people don't need them
tips on guitar selection: http://www.jitatang.com/guitar It is recommended to refer to
no matter where you buy it, you should know some experience to avoid being trapped. Generally, you will be trapped when you go to a piano shop for the first time. The most important two points (you can't hear the timbre and so on):
1. Look at the appearance and choose the log color or black directly Sunset color (the classic three color system), never white, Pink Guitar, that is the above said practice piano grade
2. Check the handle. When the guitar is tuned to the standard pitch, the distance between the string and the fingerboard should be about 3mm (that is, the thickness of a coin) at the 12th point. If you press the string too high, you will feel tired, otherwise it will cause the phenomenon of playing. A good hand feeling is that you can easily press any tone with your left finger without any proct or noise, and you don't feel any effort when you press it horizontally
3. Performance (in fact, you can't see it. You can get what you pay for. It's right to choose the most expensive one in your budget.)
Good mobile game trading platforms are:
n0.1:5173
clients provide game trading services for 70 million users. The mobile version of 5173 game trading platform's official website has a large number of games and professional teams. In order to fully meet the demands of the majority of users' online games and digital proct transactions, the online games, page games and mobile game trading procts provided by 5173 game trading platform involve game equipment, game currency, account number, point cards, agent training, props and other digital point cards
NO.4: Netease buff
Netease buff is a trading platform launched by Netease company to support steam game accessories, aiming to provide players with a more real-time, safer and more convenient game accessories trading market environment