Composition of blockchain system
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
2-The distributed database is the physical carrier of the blockchain, and the blockchain is the logical carrier of the transaction. All core nodes should contain the full of the blockchain data
3-The blockchain serializes the blocks according to time, and the blockchain is the only body of the whole network transaction data
4-The blockchain is only effective for adding, Invalid for other operations
5-public-private key verification based on asymmetric encryption
6-accounting node requires that Byzantine general problem can be solved / avoided
7-consensus progress is evolutionarily stable, that is, it will not collapse in the face of a certain amount of contradictory data of different nodes
8-consensus process can solve the problem of double spending
five characteristics of blockchain:
decentralized
e to the use of Distributed Accounting and storage, there is no centralized hardware or management organization, the rights and obligations of any node are equal, and the data blocks in the system are jointly maintained by the nodes with maintenance function in the whole system
thanks to the decentralization of blockchain, bitcoin also has the characteristics of decentralization [6]
openness
the system is open, in addition to the private information of all parties to the transaction is encrypted, the data of the blockchain is open to all, and anyone can query the blockchain data and develop related applications through the open interface, so the information of the whole system is highly transparent
autonomy
blockchain adopts consensus based specifications and Protocols (such as a set of open and transparent algorithms) to enable all nodes in the whole system to exchange data freely and safely in a de trusted environment, so that the trust in "people" is changed into the trust in machines, and any human intervention does not work
information cannot be tampered with
once the information is verified and added to the blockchain, it will be stored permanently. Unless more than 51% of the nodes in the system can be controlled at the same time, the modification of the database on a single node is invalid, so the data stability and reliability of the blockchain are extremely high<
anonymity
since the exchange between nodes follows a fixed algorithm, their data interaction does not need trust (the program rules in the blockchain will judge whether the activity is effective by themselves), so the counterparties do not need to let the counterparties generate their own trust by disclosing their identities, which is very helpful for credit accumulation.
bitcoin is a typical blockchain system, which can be studied carefully
among them, the data layer encapsulates the underlying data block and related data encryption and timestamp technologies; The network layer includes distributed networking mechanism, data transmission mechanism and data verification mechanism; The consensus layer mainly encapsulates all kinds of 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; The contract layer mainly encapsulates all kinds of scripts, algorithms and smart contracts, which is the basis of the programmable characteristics of blockchain; The 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.
1, data layer / data layer
the data layer mainly describes the physical form of blockchain, which is a chain structure starting from Genesis block on blockchain, including block data, chain structure, random number, time stamp, public and private key data on blockchain, and is the lowest level data structure in the whole blockchain technology
2. Network layer / network layer
the network layer mainly realizes the mechanism of distributed network through P2P technology, and the network layer includes P2P networking mechanism, data dissemination mechanism and data verification mechanism. Therefore, blockchain is essentially a P2P network with automatic networking mechanism, and the communication between nodes is maintained by maintaining a common blockchain structure
3. Consensus layer / consensus layer
consensus layer mainly includes consensus algorithm and consensus mechanism, which enables highly dispersed nodes to reach consensus on the effectiveness of block data efficiently in the decentralized blockchain network. It is one of the core technologies of blockchain and also the governance mechanism of blockchain community. At present, there are at least dozens of consensus mechanism algorithms, including workload proof, rights and interests proof, rights and interests authorization proof, burning proof, importance proof and so on
data layer, network layer and consensus layer are the necessary elements of building blockchain technology. Without any layer, it can not be called a real blockchain technology
4. Incentive layer / activator layer
the incentive layer mainly includes the issuing system and distribution system of economic incentive. Its function is to provide certain incentive measures, encourage nodes to participate in the security verification work in the blockchain, incorporate economic factors into the blockchain technology system, encourage nodes that comply with rules to participate in bookkeeping, and punish nodes that do not comply with rules
5. Contract layer / contract layer
the contract layer mainly includes various scripts, codes, algorithm mechanisms and smart contracts, which is the basis of block chain programming. Embedding the code into the blockchain or token, realizing the smart contract that can be customized, and automatically executing without a third party when certain constraints are met, is the foundation of the blockchain's distrust
6. Application layer / application layer
the application layer of blockchain encapsulates various application scenarios and cases, which are similar to applications on computer operating system, portals on Internet browsers, search engines, e-malls or apps on mobile phones. The blockchain technology applications are deployed on Ethereum, EOS and qtum, and are implemented in real life scenarios. The future programmable finance and programmable society will also be built on the application layer
incentive layer, contract layer and application layer are not necessary factors for each blockchain application, and some blockchain applications do not completely include the three-tier structure.
as the computing level of the whole bitcoin network continues to rise exponentially, a single device or a small amount of computing power can not get the block reward provided by bitcoin network
after the computing power of the whole network has been improved to a certain extent, the low probability of getting rewards has prompted some geeks on "bitcoin talk" to develop a method that can combine a small amount of computing power and operate jointly. The website established in this way is called "mine pool"
extended data:
the existence of the mine pool reces the difficulty of mining bitcoin and other virtual digital currencies, reces the threshold of mining, and truly realizes the concept of bitcoin mining that everyone can participate in
but its disadvantages are also very obvious, because computing power is connected to the mine pool. As a mine pool, it will have a huge amount of computing power resources. In the bitcoin world, computing power represents the bookkeeping right, and computing power is everything. If the computing power of a single mine pool reaches more than 50%, it will be easy to launch 51% attacks on bitcoin and other similar virtual digital currencies, The consequences are very terrible:
the mine pool can make the mine pool with 49% of the remaining computing power have no harvest, instantly quit the competition and go bankrupt. The mine pool's computing power exceeds 50%. If 51% attack is launched, it will easily occupy all the effective computing power of the whole network
source of reference: network mine pool
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