Blockchain s
blockchain is the underlying technology of bitcoin, like a database ledger, recording all transaction records. Because of its safety and convenience, this technology has graally attracted the attention of the banking and financial instry
in April 2018, a group of scholars from Oxford University announced the establishment of Woolf University, the world's first blockchain University
in a narrow sense, blockchain is a kind of chain data structure that combines data blocks in chronological order in a sequential way, and it can not be tampered with and forged by cryptography
broadly speaking, blockchain technology is a new distributed infrastructure and computing method, which uses blockchain data structure to verify and store data, uses distributed node consensus algorithm to generate and update data, uses cryptography to ensure the security of data transmission and access, and uses intelligent contract composed of automated script code to program and operate data.
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
First of all, don't think too much about blockchain. It's a database storage system that is distributed all over the world and can work together. Different from the traditional database operation, where the read and write permissions are controlled by a company or a centralized hand (the centralized feature), blockchain believes that anyone who has the ability to set up a server node can participate in it. Gold diggers from all over the world deploy their own nodes locally and connect to the blockchain network to become a node in the distributed database storage system; Once joined, the node enjoys the same rights and obligations as all other nodes (decentralized, distributed features). At the same time, for those who carry out services on the blockchain, they can read and write to any node in the system. Finally, all nodes in the world will synchronize one after another according to some mechanism, so that the data of all nodes in the blockchain network is completely consistent
blockchain itself is a technology, so it can't be a fraud. Just like the normalized "P2P" finance in recent years, how many fraudsters are wearing the concept of P2P to illegally absorb public funds and cheat people's hard-earned money? But is "P2P" guilty? It's just an indivial to indivial mode of Internet finance. It not only creates profits, but also helps thousands of people get rid of poverty, so as to achieve a win-win situation between the poor and the poor. The problems of currency exchange digital currency trading platform
can not hinder the development of blockchain, such as simple payment verification, side chain, lightning network protocol and other technologies proposed and in-depth research, which has been the problem solved by blockchain
Pyramid selling is harmful to family, society, indivial mind and social stability
Deng Wanhong, deputy director of Shenyang Public Security Bureau, said on the 18th that Shenyang police have successfully cracked a major pyramid selling case involving 25 provinces, autonomous regions and cities through continuous efforts. Up to now, the police suspect 24 suspects in criminal detention, and seized 364 million yuan in cash. On September 15 this year, a clue to the implementation of illegal pyramid selling activities entered the sight of Shenyang police. According to the preliminary investigation of Shenyang Public Security Bureau, the gang involved a large number of people. In September and October this year alone, it developed nearly 100000 people, involving 25 provinces, autonomous regions and cities such as Liaoning, Beijing and Tianjin. According to the preliminary statistics, the amount involved in the case reached 600 million yuan. The gang is eligible for membership by paying a membership fee of 3900 yuan per person. At that time, it will get an annual income of no less than 150000 yuan. At the same time, each member of the development of a new member, you can get a bonus of several hundred yuan In short, the existence of MLM organizations not only threatens families and indivials, but also affects social stability strong>