Blockchain HTML5
what is centralization
the so-called centralization means "ownership" or ownership by the company. For example, Tencent's q-coin, which is issued by Tencent, is a kind of centralized electronic currency, including the total amount and the issuing method, is supervised and controlled by Tencent. You can use it, trade and go shopping, but you always have to operate in the framework of Tencent, and the final right of interpretation belongs to Tencent
the issuing mode of bitcoin is preset by the program and encryption algorithm, and runs on multiple nodes all over the world. No one or organization can modify it (everyone has his own account book, so it is impossible for one person to control everyone's account book at the same time. If there is such a technology, why should it be so complicated, If you want to blackmail money into your account, you will be the richest man in the world. There is no one left, And it is not controlled by any single person or organization
take an example: for example, Lao Zhang borrows 100 yuan from Lao Li, but Lao Li is afraid that he will default, so he asks the village head to do notarization and write down the account. This is called centralization. But if you don't find the village head, you can use the loudspeaker to shout in the village: "I Lao Li lent Lao Zhang 100 yuan! Please put it in the account book. "We all put this account in our own account book. This is called decentralization
anyone who transfers money between them will release information through loudspeakers. After receiving the information, everyone will record the transaction in their own account book. With distributed ledgers, it doesn't matter if Lao Zhang or Lao Li's ledgers are lost, because Lao Zhao, Lao Ma, Lao Wang and other families have ledgers
the main advantages of blockchain are that it does not need intermediary participation, the whole process is open and transparent, and the cost is low, and the data security is high
at present, blockchain is in a stage where everyone talks about blockchain, but can't perceive its actual technical charm. Since 2017, it has graally come into our sight, and we have graally realized that bitcoin is more fierce than real estate speculation (the price of mining machinery has skyrocketed! The news is on the screen But I still don't know
so, in which fields can blockchain be applied, what kind of changes will it bring to our future life
the core key: everyone has an account book, everyone has an account book, and the information recorded in each person's account book is consistent and synchronous, and the information is completely transparent. If it is fake, it will be the public enemy of the whole people, which greatly increases the cost of data fraud
core key 2: decentralization, which does not need a central system to manage data, prevents some people from changing data and damages the interests of the majority of people
Application:
1. Account security and privacy protection: currency transfer, exchange, payment system. Blockchain can help prevent data manipulation and fraud, prevent distributed denial of service attacks (DDoS), and effectively protect users' network privacy. Key words: anti counterfeiting, anti-counterfeiting, loan payment
2. Copyright regulation and interest disputes: for example, when a song is downloaded, from the author to the procer and then to the singer, they can get payment in real time through the blockchain, without having to wait for a long time like the traditional way, or even get no reward e to right disputes. Instead of waiting for publishers to provide royalty checks, creators can freely control the process from publishing to payment through blockchain application. Key words: real time receipt, no property dispute
3. Internet of things + artificial intelligence: the intelligent devices in the Internet of things based on the blockchain will be used to monitor the real-time situation of urban infrastructure such as bridges, roads, power grids, etc. the blockchain can connect these intelligent devices together for unified management to help them monitor more efficiently. This will help people better understand how to build a smart city in the future. Key words: unified monitoring, intelligent city
4: proof of existence: in life, once you are asked to prove that you are you, that your mother is your mother, that you have never been married, that the house belongs to you, and so on, things seem very simple. Once it falls on you, it is a great trouble. The application of blockchain technology can perfectly solve the above embarrassment. At that time, all the information that belongs to you will be recorded accurately and can not be tampered with. No one has the right to change it. When the technology develops to a certain stage, birth certificate and marriage certificate may be recorded on the blockchain. Keywords: no keywords
in addition to the application scenarios mentioned above, blockchain technology can also be applied to e-commerce, data storage, logistics and other fields. As long as we grasp the characteristics of blockchain technology, it will become easy to understand.
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