Technical support for blockchain architecture
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.
broadly speaking, blockchain technology is a new distributed infrastructure and computing paradigm, 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
as we all know, blockchain technology is an independent underlying architecture from bitcoin system. From the perspective of architecture model, it is a set of distributed ledger, which is naturally used for bookkeeping
in the blockchain technology, if you want to generate accounting records, you need to have the transaction and flow of funds. Therefore, in the initial blockchain technology, the cryptocurrency corresponding to the main network is used as circulation goods, and the circulation transaction records of cryptocurrency between the accounts of the main network of the blockchain will be recorded on the main network
different from other transaction record databases, transaction records on the main network of blockchain technology will be recorded on all block nodes (i.e. all data blocks) in the main network, which is the so-called decentralization principle. That is to say, in blockchain technology, there is no central database to store all records, Every block on the chain has the transaction data of the whole chain, that is to say, every data block is the center
another feature of blockchain technology is that it can't be tampered with, because every transaction on the blockchain will be recorded in all blocks on the chain, so no single data block can change the record. Even if you change it, all other data blocks will also record real data, and each group of data can be traced back to the first time
because of these characteristics of blockchain technology, after the advent of bitcoin, blockchain has also attracted a lot of attention, and many people also began to want to use blockchain technology to make a centerless, traceable and unchangeable data, so as to ensure the credibility of the data
however, blockchain technology also faces many problems, such as single application scenario, non modifiable original error data, non recoverable currency stolen by hackers, etc.
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
1.
Lianzhuang data block structure based on blocks
2.
network wide shared ledger
3.
asymmetric encryption
4.
source code open source
the technical basis of blockchain 2.0 era is as follows:
1.
smart contract; It is an application in the blockchain system. It is a business logic that can run automatically by coding. It usually has its own token and special development language<
2
3.
virtual machine: it is used to execute the compiled code of smart contract. Virtual machine is Turing complete
with the application and deepening of blockchain technology, the era of blockchain 3.0 has come. The mode of blockchain cooperation can be seen from behind the operation of all walks of life. Therefore, blockchain will change the way of human life widely and profoundly, so the whole life service will enter the era of blockchain. In the process of Internet development, blockchain + physical instry, blockchain e-commerce and blockchain community operation can be applied to blockchain technology
of course, 3.0 came into being with the development of modern cryptography. Today's applied cryptography is the result of cryptography 20 years ago. Therefore, in order to apply blockchain technology to more participation scenarios, especially in Internet economy and other aspects, more verification is needed to verify whether the existing encryption technology can meet the demand, and more in-depth integration of cryptographic frontier technology and continuous innovation are needed.
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.)
1. Data layer: encapsulates the underlying data block and related data encryption and timestamp technologies
2. Network layer: includes distributed networking mechanism, data propagation mechanism and data verification mechanism
3. Consensus layer: it mainly encapsulates various consensus algorithms of network nodes; The incentive layer integrates economic factors into the blockchain technology system, mainly including the issuance mechanism and distribution mechanism of economic incentives
4. Contract layer: it mainly encapsulates all kinds of scripts, algorithms and smart contracts, which is the basis of the programmable characteristics of blockchain; At present, jinwowo in Southwest China has taken the lead in big data research with blockchain as the underlying technology, and also provides big data services with blockchain as the underlying technology
5. Application layer: encapsulates various application scenarios and cases of blockchain. In this model, chain block structure based on timestamp, consensus mechanism of distributed nodes, economic incentive based on consensus computing power and flexible and programmable smart contract are the most representative innovations of blockchain technology