Decentralized distributed consistency protocol
Publish: 2021-04-07 08:42:37
1. According to Hou Jietai: the so-called centralization refers to subtracting the mean value of a variable from its expected value. For sample data, each observation value of a variable is subtracted from the sample average value of the variable, and the transformed variable is centralized
for your question, subtract the mean from each measurement.
for your question, subtract the mean from each measurement.
2. Jinwowo analyzes the decentralized peer-to-peer network of blockchain. Blockchain system is a point-to-point network. All nodes in the network jointly own and maintain all data in the system, and the damage or offline of any node will not affect the operation of the whole system. Decentralization brings greater security and stability advantages to the whole network.
3. Compared with the traditional centralized storage and centralized cloud services, the two complement each other and expand the market of data storage and computing, which will constitute the two cornerstones of the future digital economy. China has efficient, stable and cheap power and network infrastructure, which provides sufficient soil for the development of decentralized cloud computing. Taking IPFs as an example, 90% of the total network computing power of IPFs is located in China. In the future, China will become the leader of IPFs. Taking xnmatrix as an example, it has become a global computing power leading decentralized cloud computing platform.
4. Due 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
in the future, jinwowo will continue to tap the value of blockchain technology in the commercial field, give full play to the advantages of big data services, add value to user behavior, break the ice for the development of small and medium-sized enterprises, and build a real, efficient, safe and honest Internet community of destiny.
in the future, jinwowo will continue to tap the value of blockchain technology in the commercial field, give full play to the advantages of big data services, add value to user behavior, break the ice for the development of small and medium-sized enterprises, and build a real, efficient, safe and honest Internet community of destiny.
5. Blockchain is a decentralized distributed ledger system, which can be used to register and issue digital assets, property rights certificates, points, etc., and transfer, pay and trade in a point-to-point manner. Compared with the traditional centralized ledger system, blockchain system has the advantages of complete disclosure, tamper proof, multiple payment prevention, and does not rely on any trusted third party
e to the high network delay in peer-to-peer network, the transaction order observed by each node can not be completely consistent. Therefore, the blockchain system needs to design a mechanism to reach a consensus on the sequence of transactions that occur in the same time. This algorithm to reach consensus on the order of transactions in a time window is called consensus mechanism
-- chainknow
e to the high network delay in peer-to-peer network, the transaction order observed by each node can not be completely consistent. Therefore, the blockchain system needs to design a mechanism to reach a consensus on the sequence of transactions that occur in the same time. This algorithm to reach consensus on the order of transactions in a time window is called consensus mechanism
-- chainknow
6. The decentralized nodes in Chongqing jinwowo analysis blockchain technology are as follows:
every central node can generate blocks and write data, so every point is a central node, or the blockchain is decentralized. In order to control the whole system, more than half of the nodes must be controlled in order to control voting, so there is no administrator in this system.
every central node can generate blocks and write data, so every point is a central node, or the blockchain is decentralized. In order to control the whole system, more than half of the nodes must be controlled in order to control voting, so there is no administrator in this system.
7. What do pow, POS and dpow mean
when it comes to blockchain, we must talk about its consensus mechanism. If we don't understand the consensus mechanism of blockchain, we can't understand the real meaning of blockchain. So, what about the consensus mechanism of today's blockchain
what is the consensus mechanism
what is consensus? Take its literal meaning, that is & quot; Common understanding & quot
people are different, not only in stature, appearance and ability, but also in culture, views, ideas, interests and so on
consensus, in short, is the consensus reached by members of a group in a certain aspect
we have learned that trust is a major pain point in the operation of society. Banks have their own credit system. In the past, the financial system only served a few entrepreneurs, because the establishment of credit system cost a lot. Later, Alipay had sesame credit. Credit has already been related to many aspects of life, credit card size, spending amount of flowers, sesame credit and high going abroad can be avoided. We are enjoying the convenience of credit
the essence of blockchain is decentralization, and the core of decentralization is consensus mechanism. The consensus mechanism on blockchain mainly solves the problems of who constructs the block and how to maintain the unity of blockchain
the goal of the blockchain consensus mechanism is to make all honest nodes save consistent blockchain views, while meeting two properties:
1) consistency: the prefix part of the blockchain saved by all honest nodes is exactly the same
2) effectiveness: the information released by an honest node will be recorded in its own blockchain by all other honest nodes
the confidence of blockchain is mainly reflected in the fact that users distributed in the blockchain do not need to trust the other party of the transaction or a centralized organization, and only need to trust the software system under the blockchain protocol to realize the transaction
what is the consensus mechanism? What do pow, POS and dpow mean
the necessity of consensus mechanism
in a distributed system, multiple hosts form a network cluster through asynchronous communication. In such an asynchronous system, state replication between hosts is needed to ensure that each host can reach a consensus. Error messages may appear in asynchronous systems and propagate continuously, so it is necessary to define fault-tolerant protocols in default unreliable asynchronous networks to ensure that all hosts reach a safe and reliable state consensus, which is the necessity of consensus mechanism
the premise of such self-confidence is the consensus mechanism of the blockchain, that is, in a market of mutual distrust, the sufficient and necessary condition for each node to reach an agreement is that each node will spontaneously and honestly abide by the pre-set rules in the agreement to judge the authenticity of each record for the sake of maximizing its own interests, Finally, the records judged to be true are recorded in the blockchain. Attachments-2018-08-9yy7vrha5b738e3d96021. JPG
in other words, if each node has its own independent interests and competes with each other, it is almost impossible for these nodes to conspire to cheat you, especially when they have public reputation in the network. Blockchain technology is the use of a set of mathematical algorithms based on consensus to establish & quot; Trust & quot; Network, so as to create new credit through technical endorsement rather than centralized credit institutions
Introction to several consensus mechanisms in today's blockchain
there are many consensus mechanisms in blockchain, but none of them is perfect, or suitable for all application scenarios
POW workload proof
each node in the whole system provides computing power (referred to as computing power) for the whole system. Through a competitive mechanism, the node with the best computing work can be rewarded by the system, that is, to complete the allocation of newly generated currency. It is simply understood that more work pays more. Currency blockchains such as bitcoin and LTC apply POW mechanism
advantages
completely decentralize the nodes to get in and out freely, the algorithm is simple, easy to realize, and the cost of destroying the system is huge. As long as the computing power of the network destroyer does not exceed 50% of the total computing power of the network, the transaction status of the network can reach an agreement
disadvantages
waste energy, which is the biggest disadvantage. It is difficult to shorten the block confirmation time, for example, bitcoin can only do 7 transactions per second, It is not suitable for commercial application. A new blockchain must find a different hash algorithm, or it will face bitcoin's computing power attack. It has high requirements on the performance of the nodes, and the network environment is prone to bifurcation. It needs to wait for multiple confirmations, and can not reach the final agreement
POS proof of equity
also known as proof of equity, which is similar to you deposit your property in the bank, This model will allocate interest to you according to the amount and time of cryptocurrency you hold< Advantages
low requirements for node performance and short consensus time
disadvantages
there is no final consistency, so checkpoint mechanism is needed to make up for the finality
dpow is an evolutionary scheme of pos. in conventional POW and POS, any newly added block needs to be confirmed by all nodes of the whole network, which greatly affects the efficiency
dpos is similar to the voting mechanism of modern board of directors, which elects representatives to vote and make decisions. The N selected accounting nodes are used for the creation, verification, signature and mutual supervision of new blocks, which greatly reces the time and computational cost of block creation and confirmation
advantages
greatly rece the number of nodes participating in verification and accounting, which can achieve second level consensus verification
disadvantages
sacrifice the concept of decentralization, which is not suitable for public chain
pbft practical Byzantine fault tolerance
practical Byzantine fault tolerance mechanism is a kind of adoption & quot; Permission to vote, minority subject to majority & quot; The consensus mechanism allows Byzantine fault tolerance, allows strong supervision nodes to participate, has the ability of authority classification, higher performance and lower energy consumption, and each round of bookkeeping will be jointly elected by the whole network nodes, allowing 33% of nodes to do evil, and the fault tolerance rate is 33%. Practical Byzantine fault tolerance is especially suitable for the application scenario of alliance chain<
advantages
will deviate from centralization, the existence of cryptocurrency and reward mechanism will proce Matthew effect, making the poor poorer and the rich richer in the community, achieving high consensus efficiency and realizing high-frequency trading
disadvantages
when only 33% of the nodes in the system are running, the system will stop running
dbft authorizes Byzantine fault tolerance
this mechanism is to use rights to select bookkeeper, Then bookkeepers reach a consensus through Byzantine fault-tolerant algorithm. The core of Byzantine fault tolerance mechanism is to ensure the system's finality to the maximum extent, so that the blockchain can be applied to real financial application scenarios
advantages
Professional bookkeeper can tolerate any type of error, bookkeeping is completed by multiple people, each block has finality, no bifurcation, the reliability of the algorithm has strict mathematical proof
disadvantages
when one-third or more bookkeepers stop working, the system will not be able to provide services, when one-third or more bookkeepers jointly commit crimes, The system may be bifurcated
pool verification pool
based on traditional distributed consistency technology and data verification mechanism
advantages
it can work without cryptocurrency. Based on the mature distributed consistency algorithms (pasox, raft), it realizes second level consensus verification
disadvantages
the degree of decentralization is not as good as bitcoin, which is more suitable for the multi center business model with multi participation
Paxos
this is a traditional distributed consensus algorithm, which is a consensus mechanism based on election leaders. The leader node has absolute authority, and allows strong supervision node to participate, which has high performance and low resource consumption. Generally, all nodes have wired access mechanism, but there is no malicious node in the election process, which is not fault-tolerant< In Paxos algorithm, nodes are divided into three types:
proposer: put forward a proposal and wait for everyone's approval. The client often plays the role
acceptor: responsible for voting on the proposal. Usually, the server plays this role
learner: is informed of the result of the case settlement, and unifies with it, and does not participate in the voting process. Maybe the client or server
Paxos can ensure that the system can reach a consensus when more than 50% of the normal nodes exist
REBO consensus mechanism
REBO consensus algorithm enables a group of nodes to form a consensus based on the special node list. The initial special node list is like a club. To accept a new member, it must be voted by 51% of the members of the club. Consensus follows the & quot; 51% rights;, Outsiders have no influence. Since the club starts with centralization, it will always be, and if it starts to corrupt, shareholders can do nothing. Like bitcoin and peercoin, the reborn system separates shareholders from their voting rights, so it is more centralized than other systems
peercoin
peercoin (PPC) is a combination of proof of pow workload and proof of POS equity. POW is mainly used to issue currency. In the future, with the increase of mining difficulty, the output will decrease, and the system security will be mainly maintained by POS
in the blockchain network, e to different application scenarios, different goals are designed, and different blockchain systems adopt different consensus algorithms. Each consensus algorithm is not perfect and has its own advantages and limitations
blockchain solves the problems of transmitting trusted information and value transfer on untrusted channels, while consensus mechanism solves the problem of how blockchain achieves consistency in distributed scenarios
although the blockchain is still in the early stage of development, and the instry development is still facing some obstacles, the society has recognized the value of the blockchain enough, the pace of blockchain development will never stop, and the instry development will certainly find a way to break through the obstacles.
when it comes to blockchain, we must talk about its consensus mechanism. If we don't understand the consensus mechanism of blockchain, we can't understand the real meaning of blockchain. So, what about the consensus mechanism of today's blockchain
what is the consensus mechanism
what is consensus? Take its literal meaning, that is & quot; Common understanding & quot
people are different, not only in stature, appearance and ability, but also in culture, views, ideas, interests and so on
consensus, in short, is the consensus reached by members of a group in a certain aspect
we have learned that trust is a major pain point in the operation of society. Banks have their own credit system. In the past, the financial system only served a few entrepreneurs, because the establishment of credit system cost a lot. Later, Alipay had sesame credit. Credit has already been related to many aspects of life, credit card size, spending amount of flowers, sesame credit and high going abroad can be avoided. We are enjoying the convenience of credit
the essence of blockchain is decentralization, and the core of decentralization is consensus mechanism. The consensus mechanism on blockchain mainly solves the problems of who constructs the block and how to maintain the unity of blockchain
the goal of the blockchain consensus mechanism is to make all honest nodes save consistent blockchain views, while meeting two properties:
1) consistency: the prefix part of the blockchain saved by all honest nodes is exactly the same
2) effectiveness: the information released by an honest node will be recorded in its own blockchain by all other honest nodes
the confidence of blockchain is mainly reflected in the fact that users distributed in the blockchain do not need to trust the other party of the transaction or a centralized organization, and only need to trust the software system under the blockchain protocol to realize the transaction
what is the consensus mechanism? What do pow, POS and dpow mean
the necessity of consensus mechanism
in a distributed system, multiple hosts form a network cluster through asynchronous communication. In such an asynchronous system, state replication between hosts is needed to ensure that each host can reach a consensus. Error messages may appear in asynchronous systems and propagate continuously, so it is necessary to define fault-tolerant protocols in default unreliable asynchronous networks to ensure that all hosts reach a safe and reliable state consensus, which is the necessity of consensus mechanism
the premise of such self-confidence is the consensus mechanism of the blockchain, that is, in a market of mutual distrust, the sufficient and necessary condition for each node to reach an agreement is that each node will spontaneously and honestly abide by the pre-set rules in the agreement to judge the authenticity of each record for the sake of maximizing its own interests, Finally, the records judged to be true are recorded in the blockchain. Attachments-2018-08-9yy7vrha5b738e3d96021. JPG
in other words, if each node has its own independent interests and competes with each other, it is almost impossible for these nodes to conspire to cheat you, especially when they have public reputation in the network. Blockchain technology is the use of a set of mathematical algorithms based on consensus to establish & quot; Trust & quot; Network, so as to create new credit through technical endorsement rather than centralized credit institutions
Introction to several consensus mechanisms in today's blockchain
there are many consensus mechanisms in blockchain, but none of them is perfect, or suitable for all application scenarios
POW workload proof
each node in the whole system provides computing power (referred to as computing power) for the whole system. Through a competitive mechanism, the node with the best computing work can be rewarded by the system, that is, to complete the allocation of newly generated currency. It is simply understood that more work pays more. Currency blockchains such as bitcoin and LTC apply POW mechanism
advantages
completely decentralize the nodes to get in and out freely, the algorithm is simple, easy to realize, and the cost of destroying the system is huge. As long as the computing power of the network destroyer does not exceed 50% of the total computing power of the network, the transaction status of the network can reach an agreement
disadvantages
waste energy, which is the biggest disadvantage. It is difficult to shorten the block confirmation time, for example, bitcoin can only do 7 transactions per second, It is not suitable for commercial application. A new blockchain must find a different hash algorithm, or it will face bitcoin's computing power attack. It has high requirements on the performance of the nodes, and the network environment is prone to bifurcation. It needs to wait for multiple confirmations, and can not reach the final agreement
POS proof of equity
also known as proof of equity, which is similar to you deposit your property in the bank, This model will allocate interest to you according to the amount and time of cryptocurrency you hold< Advantages
low requirements for node performance and short consensus time
disadvantages
there is no final consistency, so checkpoint mechanism is needed to make up for the finality
dpow is an evolutionary scheme of pos. in conventional POW and POS, any newly added block needs to be confirmed by all nodes of the whole network, which greatly affects the efficiency
dpos is similar to the voting mechanism of modern board of directors, which elects representatives to vote and make decisions. The N selected accounting nodes are used for the creation, verification, signature and mutual supervision of new blocks, which greatly reces the time and computational cost of block creation and confirmation
advantages
greatly rece the number of nodes participating in verification and accounting, which can achieve second level consensus verification
disadvantages
sacrifice the concept of decentralization, which is not suitable for public chain
pbft practical Byzantine fault tolerance
practical Byzantine fault tolerance mechanism is a kind of adoption & quot; Permission to vote, minority subject to majority & quot; The consensus mechanism allows Byzantine fault tolerance, allows strong supervision nodes to participate, has the ability of authority classification, higher performance and lower energy consumption, and each round of bookkeeping will be jointly elected by the whole network nodes, allowing 33% of nodes to do evil, and the fault tolerance rate is 33%. Practical Byzantine fault tolerance is especially suitable for the application scenario of alliance chain<
advantages
will deviate from centralization, the existence of cryptocurrency and reward mechanism will proce Matthew effect, making the poor poorer and the rich richer in the community, achieving high consensus efficiency and realizing high-frequency trading
disadvantages
when only 33% of the nodes in the system are running, the system will stop running
dbft authorizes Byzantine fault tolerance
this mechanism is to use rights to select bookkeeper, Then bookkeepers reach a consensus through Byzantine fault-tolerant algorithm. The core of Byzantine fault tolerance mechanism is to ensure the system's finality to the maximum extent, so that the blockchain can be applied to real financial application scenarios
advantages
Professional bookkeeper can tolerate any type of error, bookkeeping is completed by multiple people, each block has finality, no bifurcation, the reliability of the algorithm has strict mathematical proof
disadvantages
when one-third or more bookkeepers stop working, the system will not be able to provide services, when one-third or more bookkeepers jointly commit crimes, The system may be bifurcated
pool verification pool
based on traditional distributed consistency technology and data verification mechanism
advantages
it can work without cryptocurrency. Based on the mature distributed consistency algorithms (pasox, raft), it realizes second level consensus verification
disadvantages
the degree of decentralization is not as good as bitcoin, which is more suitable for the multi center business model with multi participation
Paxos
this is a traditional distributed consensus algorithm, which is a consensus mechanism based on election leaders. The leader node has absolute authority, and allows strong supervision node to participate, which has high performance and low resource consumption. Generally, all nodes have wired access mechanism, but there is no malicious node in the election process, which is not fault-tolerant< In Paxos algorithm, nodes are divided into three types:
proposer: put forward a proposal and wait for everyone's approval. The client often plays the role
acceptor: responsible for voting on the proposal. Usually, the server plays this role
learner: is informed of the result of the case settlement, and unifies with it, and does not participate in the voting process. Maybe the client or server
Paxos can ensure that the system can reach a consensus when more than 50% of the normal nodes exist
REBO consensus mechanism
REBO consensus algorithm enables a group of nodes to form a consensus based on the special node list. The initial special node list is like a club. To accept a new member, it must be voted by 51% of the members of the club. Consensus follows the & quot; 51% rights;, Outsiders have no influence. Since the club starts with centralization, it will always be, and if it starts to corrupt, shareholders can do nothing. Like bitcoin and peercoin, the reborn system separates shareholders from their voting rights, so it is more centralized than other systems
peercoin
peercoin (PPC) is a combination of proof of pow workload and proof of POS equity. POW is mainly used to issue currency. In the future, with the increase of mining difficulty, the output will decrease, and the system security will be mainly maintained by POS
in the blockchain network, e to different application scenarios, different goals are designed, and different blockchain systems adopt different consensus algorithms. Each consensus algorithm is not perfect and has its own advantages and limitations
blockchain solves the problems of transmitting trusted information and value transfer on untrusted channels, while consensus mechanism solves the problem of how blockchain achieves consistency in distributed scenarios
although the blockchain is still in the early stage of development, and the instry development is still facing some obstacles, the society has recognized the value of the blockchain enough, the pace of blockchain development will never stop, and the instry development will certainly find a way to break through the obstacles.
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