WO2020168477A1 - 一种联盟链共识下满足分区容忍性的拓扑构造方法及系统 - Google Patents

一种联盟链共识下满足分区容忍性的拓扑构造方法及系统 Download PDF

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WO2020168477A1
WO2020168477A1 PCT/CN2019/075547 CN2019075547W WO2020168477A1 WO 2020168477 A1 WO2020168477 A1 WO 2020168477A1 CN 2019075547 W CN2019075547 W CN 2019075547W WO 2020168477 A1 WO2020168477 A1 WO 2020168477A1
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probability
partition
partition tolerance
alliance chain
state
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French (fr)
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李挥
王菡
邬江兴
伊鹏
陆平
安辉耀
黄健森
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Foshan Saisichan Tech Co Ltd
Shenzhen Cestbon Technology Co Ltd
Peking University Shenzhen Graduate School
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Foshan Saisichan Tech Co Ltd
Shenzhen Cestbon Technology Co Ltd
Peking University Shenzhen Graduate School
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Priority to CN201980005054.8A priority patent/CN111512332B/zh
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    • G—PHYSICS
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Definitions

  • the invention belongs to the technical improvement field of network construction, and in particular relates to a topology construction method that satisfies the partition tolerance under the alliance chain consensus.
  • Blockchain refers to the construction of unforgeable, non-tamperable and traceable block-chain data in a peer-to-peer network (Peer-to-Peer Networking, also known as peer-to-peer network) environment through transparent and trusted rules Structure to implement and manage the transaction processing mode.
  • Peer-to-Peer Networking also known as peer-to-peer network
  • a blockchain is a chained data structure that combines data blocks in a chronological order and is not tamperable with cryptographic methods.
  • blockchain uses block-chain data structures to verify and store data, uses distributed node consensus algorithms to generate and update data, and uses cryptography to ensure data transmission and access A new distributed infrastructure and calculation method that safely uses smart contracts composed of automated script codes to program and manipulate data.
  • the blockchain is essentially a decentralized distributed ledger, and long before the emergence of the blockchain, the idea of distributed has been proposed and matured day by day.
  • Consistency Consistency
  • availability A: Availability
  • partition tolerance Partition tolerance
  • Lynch et al. proved this conjecture and raised it to the CAP theorem.
  • the CAP theorem refines the three factors of consistency, availability, and partition tolerance as important features of distributed system design.
  • Consistency means that any operation in the system should appear to be "atomic" or serial, and all operations appear to be globally ordered;
  • Availability means that any normal node will be Responses should be given within a limited time;
  • Partition tolerance means that when the network is partitioned at a certain moment, the system can still meet consistency and availability.
  • Bitcoin uses an Internet-based peer-to-peer distributed network architecture, and each node has a network routing function. When a new node needs to be connected to the Bitcoin network, perform the following steps:
  • the node After the startup is completed, the node will remember the recently successfully connected node, and can quickly re-establish a connection with the previous node after restarting. If none of the previous nodes can be connected, start from step (1) again.
  • PoA Proof of Authority
  • the same signer can only sign one of (SIGNER_COUNT/2)+1 blocks.
  • one signer at each height is in the IN-TURN state, and other signers are in the OUT-OF-TURN state.
  • the signer in the IN-TURN state can immediately broadcast their own block, OUT-OF -When a signer in TURN state generates a block, it will be broadcast after a random delay.
  • the PoA consensus relies on an effective and trustworthy identity authentication mechanism. Considering that the identity of the signer is open to the entire network, once an attacker attacks more than half of the signers, the system cannot guarantee the correctness of the block. On the other hand, compared with the traditional PBFT consensus algorithm, the PoA consensus algorithm achieves high availability and partition tolerance by weakening the consistency requirement to non-consistency (Aura client) or eventual consistency (Clique client).
  • the purpose of the present invention is to provide a topology construction method that satisfies the partition tolerance under the alliance chain consensus, and aims to solve the above technical problems.
  • the present invention is realized in this way, a topology construction method that satisfies the partition tolerance under the alliance chain consensus, and the topology construction method includes the following steps:
  • step S2 the Markov process converges to a steady-state distribution of an independent initial distribution, and obtaining the steady-state probability of the system under a single network topology includes the following steps:
  • a further technical solution of the present invention is: the MTBF and MTTR of each analysis element in step S3 are independent processes without memory and have a constant mean value; obtaining the partition tolerance probability of the system under a single network topology includes the following steps:
  • the total probability formula is: l indicates the total number of channels, and i indicates that there are and only i channels in the steady state system are in a fault state.
  • a further technical solution of the present invention is: obtaining the average minimum repair time of the system under a single network topology structure includes the following steps:
  • the further technical solution of the present invention is: in the hierarchical network topology, according to the consensus process, the partition tolerance of the lower-level domain is not only affected by its own network topology, but also related to the partition tolerance of the higher-level domain; the partition tolerance of the system Probability is
  • the average minimum repair time of the system is the average minimum repair time of the system.
  • Another object of the present invention is to provide a topology construction system that satisfies the partition tolerance under the alliance chain consensus, and the topology construction system includes
  • the combination module is used to combine the alliance chain consensus mechanism with the network topology to make the alliance chain consensus meet the partition tolerance in probability;
  • Convergence module used to abstract the partition tolerance of the system into a kind of convergent Markov process and obtain the steady-state probability of the system
  • Sampling estimation module used to estimate the probability and minimum repair time of partition failure and not meet the consistency or availability when the number of faulty channels is certain, and obtain the partition tolerance probability and average minimum repair time of the system;
  • a further technical solution of the present invention is that the Markov process in the convergence module converges to a steady-state distribution of an independent initial distribution, and obtaining the steady-state probability of the system under a single network topology includes
  • the cyclic multiplication unit is used to cyclically multiply the state transition matrix P with itself;
  • the judgment unit is used to judge whether the matrix 2-norm of the difference between two consecutive products is less than the set convergence accuracy. If it is less, then the power of P at this time is considered to be the steady-state probability matrix P * , if not less than, Then return to the loop multiplication unit.
  • a further technical solution of the present invention is: the MTBF and MTTR of each analysis element in the sampling estimation module are independent processes without memory and have a constant mean; obtaining the partition tolerance probability of the system under a single network topology includes
  • Sampling unit used to sample N times for each possible state of the steady-state system
  • the estimation unit is used to estimate the probability of partition failure in each state and not meeting consistency or availability
  • the calculation unit is used to calculate the partition tolerance probability of the system according to the total probability formula.
  • the total probability formula is:
  • l indicates the total number of channels
  • i indicates that there are and only i channels in the steady state system are in a fault state.
  • the further technical solution of the present invention is: obtaining the average minimum repair time of the system under a single network topology structure includes
  • the further technical solution of the present invention is: in the hierarchical network topology, according to the consensus process, the partition tolerance of the lower-level domain is not only affected by its own network topology, but also related to the partition tolerance of the higher-level domain; the partition tolerance of the system Probability is
  • the average minimum repair time of the system is the average minimum repair time of the system.
  • the beneficial effects of the present invention are: the network topology is combined with the alliance chain consensus mechanism, so that the alliance chain consensus meets the partition tolerance in probability, and can realize the coexistence of the three CAP factors, which has high practical significance;
  • the mean time between failures and mean time to repair that remain constant over a period of time are used as parameters to improve the Markov model's prediction accuracy for the probability distribution trend of the system state; when the number of failed channels is estimated, the partition failure occurs and does not meet the consistency or availability. Probability and minimum repair time are adapted to the partition tolerance of the consensus mechanism and the characteristics of the network topology to the greatest extent.
  • Figure 1 is a schematic diagram of the Markov state transition diagram of the general network topology.
  • Figure 2 is a schematic diagram of the domain numbering of the hierarchical network topology provided by an embodiment of the present invention.
  • FIG. 3 is a schematic diagram of the partition tolerance probability of a multi-dimensional hypersquare network topology provided by an embodiment of the present invention.
  • Fig. 4 is a schematic diagram of the average minimum repair time of the multi-dimensional hypersquare network topology provided by an embodiment of the present invention.
  • FIG. 5 is a schematic diagram of the partition tolerance probability of a multipoint fully connected network topology provided by an embodiment of the present invention.
  • FIG. 6 is a schematic diagram of the average minimum repair time of the multipoint fully connected network topology provided by an embodiment of the present invention.
  • Fig. 7 is a schematic diagram of the lower boundary of the hierarchical network topology provided by an embodiment of the present invention.
  • Figure 8 is a schematic diagram of a fully symmetric hierarchical network topology provided by an embodiment of the present invention.
  • Fig. 9 is a schematic diagram of a semi-symmetric hierarchical network topology according to an embodiment of the present invention.
  • Fig. 10 is a schematic diagram of an asymmetric hierarchical network topology provided by an embodiment of the present invention.
  • FIG. 11 is a flowchart of a topology construction method that satisfies partition tolerance under the alliance chain consensus provided by an embodiment of the present invention.
  • the present invention provides a topology construction method that satisfies partition tolerance under the alliance chain consensus, which is detailed as follows:
  • the existing blockchain system only strengthens the two factors of consistency, availability, and partition tolerance at the consensus level, and is accompanied by a significant weakening of the third factor, which is still far from the CAP limit.
  • the current mainstream blockchain systems do not consider how to maintain the network topology, which brings potential network communication risks and waste of resources.
  • the present invention a topology construction method and system that meets the tolerance of partitions under the consensus of the alliance chain, combines the network topology with the consensus mechanism of the alliance chain, so that the consensus of the alliance chain meets the tolerance of the partition in probability, and then Able to achieve the coexistence of the three factors of CAP.
  • the present invention also proposes a partition tolerance calculation method, which abstracts the partition tolerance of the system into a kind of convergent Markov process, and uses MATLAB and other simulation software to sample and calculate the network that does not meet the consistency or availability when a partition failure occurs. Probability and average minimum repair time.
  • the present invention specifically analyzes the resource overhead and partition tolerance under different network topologies, and constructs a network topology structure with suitable scale and high partition tolerance for alliance chain consensus with different requirements.
  • the technical scheme of the present invention combines the network topology and the alliance chain consensus mechanism on the basis of not affecting the consistency and availability of the consensus algorithm itself, so that the alliance chain consensus satisfies the partition tolerance in probability, thereby achieving the three factors of CAP Coexistence has high practical significance.
  • a calculation method of partition tolerance is proposed.
  • the partition tolerance problem of the system is abstracted into a kind of convergent Markov process.
  • the mean time between failures and mean time to repair are used as parameters to improve the Markov model’s
  • the prediction accuracy of the trend of the system state probability distribution is proposed.
  • the calculation method under a single network topology structure further derives the partition tolerance under the hierarchical network topology structure, which is not only suitable for general single-chain architecture, but also for multi-chain and cross-chain architecture, and has broad application prospects.
  • Domains at different levels may adopt the same or different network topologies and parameters, and the network topologies of different domains at the same level may not be exactly the same.
  • MTBF Mel Time Between Failures, Mean Time Between Failures
  • MTTR Mel Time To Repair, Mean Time To Repair
  • MTBF is much greater than MTTR.
  • v Total number of network nodes.
  • ⁇ the probability of failure interruption per unit time of the channel
  • ⁇ the probability that a channel in a faulty state in the system is repaired per unit time, namely
  • v nodes and l channels make a Markov state transition diagram, as shown in Figure 1.
  • the i-th system state indicates that there are and only i channels in the network are in a fault state (0 ⁇ i ⁇ l).
  • the state transition matrix of the Markov model is a matrix P with a scale of (l+1) ⁇ (l+1), where the element p ji represents the probability of transitioning from the i-th system state to the j-th system state.
  • m denote the number of the same failed channels in state i and state j, and the value range of m is [max ⁇ i+jl, 0 ⁇ , min ⁇ i, j ⁇ ].
  • each system state can come from any other state, that is, the Markov state transition diagram above is fully connected, so P satisfies the irreducibility.
  • Algorithm 1 describes the iterative calculation process of the system steady-state probability. Multiply the state transition matrix P by itself. If the matrix 2-norm of the difference between two consecutive products is less than the given convergence accuracy, then the power of P at this time is considered to be the steady-state probability matrix P * .
  • Algorithm 2 describes the calculation process of the partition tolerance probability of the system under a single network topology. For the various states that the system may be in at steady state, sample N times respectively, estimate the probability of partition failure and not meet consistency or availability, and then calculate the partition tolerance probability of the system according to the full probability formula.
  • the minimum repair time is defined as the minimum time required for the system to repair some channels when a certain failure occurs, so that the system meets consistency and availability.
  • Algorithm 3 describes the calculation process of the average minimum repair time of the system under a single network topology. On the basis of Algorithm 2, for each instance that has a partition failure and does not meet consistency or availability, calculate its minimum repair time, and then multiply it by the weight of the instance in the total system partition tolerance problem to get the average of the system Minimum repair time.
  • each domain is numbered according to a tree structure of (i 1 i 2 i 3 ...), as shown in Figure 2.
  • the partition tolerance of the lower-level domain is not only affected by its own network topology, but also related to the partition tolerance of the higher-level domain. make Represents the partition tolerance probability of each domain. Then the partition tolerance probability of the system is
  • the following is to calculate the partition tolerance probability and the average minimum repair time when the Proof of Vote consensus mechanism (Proof of Vote, PoV) in the alliance chain adopts the hypersquare network topology and the fully connected network topology.
  • a digital optical cable communication system with automatic switching of main and standby systems should meet the annual indicators shown in Table 1. Therefore, taking parameters ( ⁇ , ⁇ ) ⁇ ⁇ ( 4.5662 ⁇ 10 -4, 4.1667 ⁇ 10 -2), (2.7397 ⁇ 10 -4, 6.9444 ⁇ 10 -2), (3.8358 ⁇ 10 -5, 4.9603 ⁇ 10 - 1 ), (2.5571 ⁇ 10 -5 , 7.4405 ⁇ 10 -1 ) ⁇ .
  • Table 2 shows the resource overhead of the two network topologies of multi-dimensional hyper-square and multi-point full connection.
  • Figure 7 shows the lower boundary of this method, that is, the top-level, second-level, and third-level domains are all 2-dimensional hypersquare topological structures;
  • Figure 8 shows a completely symmetrical 3-level topology construction method, the top level The topological structures of the second, second, and third-level domains are all 3-dimensional hypersquares;
  • Figure 9 shows a semisymmetric 2-level topology construction method.
  • the topological structure of the same-level domains is the same, but the top-level domain topology is 4
  • the topological structure of the second-level domain is a 3-dimensional hyper-square;
  • Figure 10 shows an asymmetric 2-level topology construction method.
  • the topological structure of the upper and lower domains and the same-level domains are different. Specifically , The top-level domain adopts a 4-dimensional hyper-square structure, while there are 4, 8, and 4 secondary domains using 4-dimensional hyper-square, 3-dimensional hyper-square and 7-point fully connected structures.
  • the partition tolerance probability and the average minimum repair time of the four hierarchical network topologies in Figure 7 to Figure 10 are further calculated as:
  • t [t 1 *(1-p 1 )+t 11 *p 1 *(1-p 11 )*4+t 111 *p 1 *p 11 *(1-p 111 )*4*4]/( 1-p) ⁇ 21h, that is, the average minimum repair time after a partition failure occurs is about 21 hours.
  • t [t 1 *(1-p 1 )+t 11 *p 1 *(1-p 11 )*8+t 111 *p 1 *p 11 *(1-p 111 )*8*8]/( 1-p) ⁇ 23h, that is, the average minimum repair time after a partition failure occurs is about 23 hours.
  • p 1-[(1-p 1 )+p 1 *(1-p 11 )*16] ⁇ 1-1 ⁇ 10 -8 , that is, a partition failure failure occurs approximately every 11,416 years.
  • t [t 1 *(1-p 1 )+t 11 *p 1 *(1-p 11 )*16]/(1-p) ⁇ 14h, that is, the average minimum repair time after a partition failure occurs is approximately 14 hours.
  • p 1-[(1-p 1 )+p 1 *(1-p 11 )*4+p 1 *(1-p 12 )*8+p 1 *(1-p 13 )*4] ⁇ 1 -6 ⁇ 10 -9 , that is, a partition failure occurs approximately every 19,026 years.
  • t [t 1 *(1-p 1 )+t 11 *p 1 *(1-p 11 )*4+t 12 *p 1 *(1-p 12 )*8+t 13 *p 1 *( 1-p 13 )*4]/(1-p) ⁇ 14h, that is, the average minimum repair time after a partition failure occurs is approximately 14 hours.
  • Another object of the present invention is to provide a topology construction system that satisfies the partition tolerance under the alliance chain consensus, and the topology construction system includes
  • the combination module is used to combine the alliance chain consensus mechanism with the network topology to make the alliance chain consensus meet the partition tolerance in probability;
  • the convergence module is used to abstract the partition tolerance of the system into a kind of convergent Markov process and obtain the steady-state probability of the system;
  • Sampling estimation module used to estimate the probability and minimum repair time of partition failure and not meet the consistency or availability when the number of faulty channels is certain, and obtain the partition tolerance probability and average minimum repair time of the system;
  • the Markov process in the convergence module converges to a steady-state distribution of an independent initial distribution, and obtaining the steady-state probability of the system under a single network topology includes
  • the cyclic multiplication unit is used to cyclically multiply the state transition matrix P with itself;
  • the judgment unit is used to judge whether the matrix 2-norm of the difference between two consecutive products is less than the set convergence accuracy. If it is less, then the power of P at this time is considered to be the steady-state probability matrix P * , if not less than, Then return to the loop multiplication unit.
  • the MTBF and MTTR of each analysis element in the sampling estimation module are independent processes without memory and the mean value is constant; obtaining the partition tolerance probability of the system under a single network topology includes
  • the estimation unit is used to estimate the probability of partition failure in each state and not meeting consistency or availability
  • the calculation unit is used to calculate the partition tolerance probability of the system according to the total probability formula.
  • the total probability formula is:
  • l indicates the total number of channels
  • i indicates that there are and only i channels in the steady state system are in a fault state.
  • the partition tolerance of the lower-level domain is not only affected by its own network topology, but also related to the partition tolerance of the higher-level domain;
  • the partition tolerance probability of the system is The average minimum repair time of the system is among them, Indicates the partition tolerance probability of each domain, Indicates the average minimum repair time of each domain.

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Abstract

一种联盟链共识下满足分区容忍性的拓扑构造方法，应用于网络构建技术改进领域，所述方法包括：将联盟链共识机制与网络拓扑结构相结合使联盟链共识在概率上满足分区容忍性（S1）；将系统的分区容忍性抽象为一类可收敛的Markov过程并获取系统的稳态概率（S2）；估算故障信道数量一定时发生分区故障且不满足一致性或可用性的概率及最小修复时间，得到系统的分区容忍概率及平均最小修复时间（S3）；根据得到的分区容忍概率及平均最小修复时间分析不同网络拓扑结构下的资源开销和分区容忍性，为不同需求的联盟链共识构造规模适合、分区容忍性高的网络拓扑结构（S4）。该方法能够实现CAP三个因素的共存，具有很高的现实意义。

Description

一种联盟链共识下满足分区容忍性的拓扑构造方法及系统 技术领域
本发明属于网络构建技术改进领域，尤其涉及一种联盟链共识下满足分区容忍性的拓扑构造方法。
背景技术
区块链，指的是一种在对等网络(Peer-to-Peer Networking，又称点对点网络)环境下，通过透明和可信规则，构建不可伪造、不可篡改和可追溯的块链式数据结构，来实现和管理事务处理的模式。根据人们早期对区块链的讨论，狭义上，区块链是一种按照时间顺序将数据区块以顺序相连的方式组合成的一种链式数据结构，并以密码学方式保证的不可篡改和不可伪造的分布式账本；广义上，区块链是利用块链式数据结构来验证和存储数据、利用分布式节点共识算法来生成和更新数据、利用密码学的方式保证数据传输和访问的安全、利用由自动化脚本代码组成的智能合约来编程和操作数据的一种全新的分布式基础架构与计算方式。
区块链本质上是一种去中心化的分布式账本，而早在区块链出现以前，分布式的思想就已经被提出并日益发展成熟。2000年，Eric Brewer在某个研讨会上提出猜想：一致性(C：Consistency)、可用性(A：Availability)和分区容忍性(P：Partition tolerance)三者无法在分布式系统中同时被完全满足。2002年，Lynch等人证明了这个猜想，并将其上升为CAP定理。CAP定理首次将一致性、可用性和分区容忍性三个因素提炼为分布式系统设计的重要特征。具体地，(1)一致性指系统中任何的操作都应该看起来是“原子”或串行的，所有的操作都看起来像被全局排序；(2)可用性指任何正常节点受到请求后都应该在有限的时间内给出响应；(3)分区容忍性指当网络在某一时刻发生分区时，系统仍然能够满足一致性和可用性。
由于区块链的网络环境十分复杂，PoW等主流区块链共识算法通过弱化严格一致性为长时间的最终一致性来满足高可用性和分区容忍性，但这会导致系统的TPS性能受限。因此，EOS等一些高性能的区块链系统选择牺牲部分分区容忍性，通过控制参与记账的节点数量来换取TPS性能的提升。上述两种手段都只是在一致性、可用性和分区容忍性中选择两个因素作为主要强化的点，而大幅度弱化第三个因素，距离CAP极限还有很大的空间。
比特币采用了基于互联网的点对点分布式网络架构，每个节点都具备网络路由功能。当一个新节点需要接入到比特币网络中时，执行以下步骤：
1.使用DNS种子或seednode命令寻找到比特币网络中的有效节点。
2.向发现的有效比特币节点发送一条包含基本认证内容的version消 息进行初始握手通信过程，建立连接。
3.将自己的IP地址发送给已连接的节点，这些节点收到后将此转发给它们各自的连接节点，使网络中有更多的节点接收到新节点。
4.向已连接节点请求其已知的节点IP地址列表，从而找到更多可连接的节点。
5.定期向已建立连接的节点发送信息维持连接，如果与某个节点之间长达90分钟没有通信，则被认为已经断开，开始寻找一个新的节点。由于比特币通信基于TCP协议，每个节点的TCP连接数有限，因此超过数量的IP地址会被忽略。
启动完成后，节点会记住最近成功连接的节点，当重新启动后可以迅速与先前的节点重新建立连接。如果先前节点均无法连接，则重新从步骤(1)开始执行。
在比特币区块链节点间通信过程中，不要求维护网络的拓扑结构，也就是不需要将网络进行逻辑意义上抽象，采用泛洪策略进行数据的传输。泛洪思想简单易于实现，而且节点加入、离开以及失效等行为对整个系统的负面影响较小，网络可靠性高。但是，由于网状结构互相连通，泛洪有可能引起节点多次重复收到相同的数据，导致节点信息冗余接收，大量无用的重复数据传输也消耗着网络资源。
基于联盟链的一类权威证明(Proof of Authority，PoA)共识算法由以太坊联合创始人兼前首席技术官Gavin Wood于2017年提出，目前用在以太坊测试网Kovan中。PoA的共识流程为：首先在创世区块中指定一组初始授权的签名者，启动挖矿后签名者开始对生成的区块进行签名并广播上链。如果其他已授权的签名者反对该区块生成，则对该区块的签名者进行“踢出”投票，票数超过签名者总数的50％即取消区块对应签名者的记账权。
为了减少恶意签名者带来的损失，同一个签名者只能签名(SIGNER_COUNT/2)+1个区块中的一个。为了降低分叉的概率，每一高度都有一个签名者处于IN-TURN状态，其他签名者处于OUT-OF-TURN状态，IN-TURN状态的签名者能够立刻广播自己的区块，OUT-OF-TURN状态的签名者生成区块时则会随机延时一段时间后再广播。
PoA共识依赖于有效且值得信赖的身份认证机制。考虑到签名者的身份是向全网公开的，一旦攻击者攻击了超过半数的签名者，则系统无法保证区块的正确性。另一方面，相较传统的PBFT共识算法，PoA共识算法通过弱化一致性需求为无一致性(Aura客户端)或最终一致性(Clique客户端)，来达到高可用性和分区容忍性。
发明内容
本发明的目的在于提供一种联盟链共识下满足分区容忍性的拓扑构造方法，旨在解决上述的技术问题。
本发明是这样实现的，一种联盟链共识下满足分区容忍性的拓扑构造方法，所述拓扑构造方法包括以下步骤：
S1、将联盟链共识机制与网络拓扑结构相结合使联盟链共识在概率上满足分区容忍性；
S2、将系统的分区容忍性抽象为一类可收敛的Markov过程并获取系统的稳态概率；
S3、估算故障信道数量一定时发生分区故障且不满足一致性或可用性的概率及最小修复时间，得到系统的分区容忍概率及平均最小修复时间；
S4、根据得到的分区容忍概率及平均最小修复时间分析不同网络拓扑结构下的资源开销和分区容忍性，为不同需求的联盟链共识构造规模适合、分区容忍性高的网络拓扑结构。
本发明的进一步技术方案是：所述步骤S2中Markov过程收敛于一个独立初始分布的稳态分布，在单一网络拓扑结构下获取系统的稳态概率包括以下步骤：
S21、将状态转移矩阵P循环与自身相乘；
S22、判断连续两次乘积之差的矩阵2-范数是否小于设定的收敛精度，若小于，则认为此时的P的幂值为稳态概率矩阵P *，若不小于，则返回步骤S21。
本发明的进一步技术方案是：所述步骤S3中各个分析元素的MTBF和MTTR都是无记忆的独立过程且均值恒定；在单一网络拓扑结构下获取系统的分区容忍概率包括以下步骤：
S311、对于稳态系统的每个可能状态分别抽样N次；
S312、估计每个状态下发生分区故障且不满足一致性或可用性的概率；
S313、再根据全概率公式计算系统的分区容忍概率，全概率公式为：
Figure PCTCN2019075547-appb-000001
l表示信道总数，i表示稳态系统中有且仅有i条信道处于故障状态。
本发明的进一步技术方案是：在单一网络拓扑结构下获取系统的平均最小修复时间包括以下步骤：
S321、对每一个发生分区故障且不满足一致性或可用性的样本计算最小修复时间；
S322、乘以该样本在总系统分区容忍问题中所占的权重，得到系统的平均最小修复时间。
本发明的进一步技术方案是：在层级化网络拓扑结构中，根据共识的过程，下级域的分区容忍不仅受自身的网络拓扑结构影响，还与高层级域的分区容忍性有关；系统的分区容忍概率为
Figure PCTCN2019075547-appb-000002
系统的平均最小修复时间为
Figure PCTCN2019075547-appb-000003
其中，
Figure PCTCN2019075547-appb-000004
表示各个域的分区容忍概率，
Figure PCTCN2019075547-appb-000005
表示各个域的平均最小修复时间。
本发明的另一目的在于提供一种联盟链共识下满足分区容忍性的拓扑构造系统，所述拓扑构造系统包括
结合模块，用于将联盟链共识机制与网络拓扑结构相结合使联盟链共识在概率上满足分区容忍性；
收敛模块，用于将系统的分区容忍性抽象为一类可收敛的Markov过程并获取系统的稳态概率；
抽样估计模块，用于估算故障信道数量一定时发生分区故障且不满足一致性或可用性的概率及最小修复时间，得到系统的分区容忍概率及平均最小修复时间；
构建网络模块，用于根据得到的分区容忍概率及平均最小修复时间分析不同网络拓扑结构下的资源开销和分区容忍性，为不同需求的联盟链共识构造规模适合、分区容忍性高的网络拓扑结构。
本发明的进一步技术方案是：所述收敛模块中Markov过程收敛于一个独立初始分布的稳态分布，在单一网络拓扑结构下获取系统的稳态概率包括
循环相乘单元，用于将状态转移矩阵P循环与自身相乘；
判断单元，用于判断连续两次乘积之差的矩阵2-范数是否小于设定的收敛精度，若小于，则认为此时的P的幂值为稳态概率矩阵P *，若不小于，则返回循环相乘单元。
本发明的进一步技术方案是：所述抽样估计模块中各个分析元素的MTBF和MTTR都是无记忆的独立过程且均值恒定；在单一网络拓扑结构下获取系统的分区容忍概率包括
抽样单元，用于对于稳态系统的每个可能状态分别抽样N次；
估计单元，用于估计每个状态下发生分区故障且不满足一致性或可用性的概率；
计算单元，用于再根据全概率公式计算系统的分区容忍概率，全概率公式为：
Figure PCTCN2019075547-appb-000006
l表示信道总数，i表示稳态系统中有且仅有i条信道处于故障状态。
本发明的进一步技术方案是：在单一网络拓扑结构下获取系统的平均最小修复时间包括
计算最小修复时间单元，用于对每一个发生分区故障且不满足一致性或可用性的样本计算最小修复时间；
计算平均最小修复时间单元，用于乘以该样本在总系统分区容忍问题中所占的权重，得到系统的平均最小修复时间。
本发明的进一步技术方案是：在层级化网络拓扑结构中，根据共识的过程，下级域的分区容忍不仅受自身的网络拓扑结构影响，还与高层级域的分区容忍性有关；系统的分区容忍概率为
Figure PCTCN2019075547-appb-000007
系统的平均最小修复时间为
Figure PCTCN2019075547-appb-000008
其中，
Figure PCTCN2019075547-appb-000009
表示各个域的分区容忍概率，
Figure PCTCN2019075547-appb-000010
表示各个域的平均最小修复时间。
本发明的有益效果是：将网络拓扑结构与联盟链共识机制相结合，使得联盟链共识在概率上满足分区容忍性，进而能够实现CAP三个因素的共存，具有很高的现实意义；采用在一段时间内保持不变的平均故障间隔时间和平均故障修复时间作为参数，提高Markov模型对于系统状态概率分布趋势的预测准确度；估算故障信道数量一定时发生分区故障且不满足一致性或可用性的概率及最小修复时间，最大程度适应了共识机制的自身分区容忍性和网络拓扑结构特征。
附图说明
图1是一般网络拓扑结构的Markov状态转移图示意图。
图2是本发明实施例提供的层级化网络拓扑结构的域编号示意图。
图3是本发明实施例提供的多维超方形网络拓扑结构的分区容忍概率示意图。
图4是本发明实施例提供的多维超方形网络拓扑结构的平均最小修复时间示意图。
图5是本发明实施例提供的多点全连接网络拓扑结构的分区容忍概率示意图。
图6是本发明实施例提供的多点全连接网络拓扑结构的平均最小修复时间示意图。
图7是本发明实施例提供的层级化网络拓扑结构的下边界情况示意图。
图8是本发明实施例提供的完全对称层级化网络拓扑结构示意图。
图9是本发明实施例提供的半对称层级化网络拓扑结构示意图。
图10是本发明实施例提供的不对称层级化网络拓扑结构示意图。
图11是本发明实施例提供的联盟链共识下满足分区容忍性的拓扑构造方法的流程图。
具体实施方式
如图11所示，本发明提供的一种联盟链共识下满足分区容忍性的拓扑构造方法，其详述如下：
现有的区块链系统仅在共识层面强化了一致性、可用性和分区容忍性中的两个因素，并伴随了第三个因素的大幅弱化，较CAP极限仍有距离。此外，在数据通信层面，目前主流的区块链系统对如何维护网络拓扑结构均没有考虑，这带来了潜在的网络通信隐患和资源浪费。
针对上述问题，本发明——一种联盟链共识下满足分区容忍性的拓扑构造方法与系统，将网络拓扑结构与联盟链共识机制相结合，使得联盟链共识在概率上满足分区容忍性，进而能够实现CAP三个因素的共存。本发明还提出一种分区容忍性计算方法，将系统的分区容忍问题抽象为一类可收敛的Markov过程，并使用MATLAB等仿真软件抽样和计算网络在发生分区故障时不满足一致性或可用性的概率和平均最小修复时间。根据上述计算方法，本发明具体分析不同网络拓扑结构下的资源开销和分区容忍性，为不同需求的联盟链共识构造规模适合、分区容忍性高的网络拓扑结构。
本发明技术方案在不影响共识算法自身一致性和可用性的基础上，将网络拓扑结构与联盟链共识机制相结合，使得联盟链共识在概率上满足分区容忍性，进而能够实现CAP三个因素的共存，具有很高的现实意义。
提出一种分区容忍性计算方法，将系统的分区容忍问题抽象为一类可收敛的Markov过程，采用在一段时间内保持不变的平均故障间隔时间和平均故障修复时间作为参数，提高Markov模型对于系统状态概率分布趋势的预测准确度。
不同共识机制的分区容忍性不同，不同网络拓扑下可能发生分区故障的情况也不同，因此它们的故障概率具有各异性特征。使用MATLAB等仿真软件抽样估计故障信道数量一定时发生分区故障且不满足一致性或可用性的概率及最小修复时间，最大程度适应了共识机制的自身分区容忍性和网络拓扑结构特征。
由单一网络拓扑结构下的计算方法进一步推导层级化网络拓扑结构下的分区容忍性，不仅适用于一般的单链架构，也适用于多链和跨链架构，具有广阔的应用前景。
具体分析不同网络拓扑结构下的资源开销和分区容忍性，为不同需求的联盟链共识构造规模适合、分区容忍性高的单一或层级化网络拓扑结构。不同层级的域可以采用相同或不同的网络拓扑结构和参数，同一层级不同域的网络拓扑也可以不完全相同。
评价通信网络一般建立在以下基本假设基础上：
1.参与分析的所有元素只有两种状态：工作和故障。
2.各个分析元素之间发生故障和修复是互相独立的。
3.各个分析元素的MTBF(Mean Time Between Failures，平均故障间隔时间)和MTTR(Mean Time To Repair，平均故障修复时间)都是无记忆的独立过程且均值恒定。
4.MTBF远大于MTTR。
基于上述假设，由于每个元素均处于工作-故障-修复的多次过程，可以采用Markov过程来进行数学描述。定义参数如下：
v：网络节点总数。
l：网络信道总数。
k：联盟链共识机制满足一致性和可用性最少需要的共识节点数量，即当且仅当某个分区内的共识节点数量≥k，此联盟链共识机制满足一致性和可用性。
λ：信道单位时间内故障中断的概率，即
Figure PCTCN2019075547-appb-000011
μ：系统中某条处于故障状态的信道单位时间内被修复的概率，即
Figure PCTCN2019075547-appb-000012
一、单一网络拓扑结构的分区容忍概率和平均最小修复时间
对于一个包含了v个节点和l条信道的网络拓扑结构(如多维超方形结构或多点全连接结构)，作Markov状态转移图，如图1所示。第i个系统状态表示该网络中有且仅有i条信道处于故障状态(0≤i≤l)。
该Markov模型的状态转移矩阵是一个规模为(l+1)×(l+1)的矩阵P，其中元素p ji表示从第i个系统状态转移到第j个系统状态的概率。令m表示状态i与状态j中相同的故障信道的数量，则m的取值范围是[max{i+j-l，0}，min{i，j}]。
Figure PCTCN2019075547-appb-000013
上述Markov模型的状态转移矩阵P满足三个特性：
1.由于P的所有元素都大于等于0，且某一列的元素和表示给定初始状态下所有可能下一跳的概率之和，即P的列和均为1，因此P满足随机性。
2.由于各个信道之间发生故障和修复是互相独立的，每一个系统状态都可来自任意的其他状态，即上述Markov状态转移图是全连通的，所以P满足不可约性。
3.由图1可知，系统状态间不存在简单循环，因此P满足非周期性。
因此，上述Markov过程最终会收敛到一个独立于初始分布的稳态分布。算法1描述了系统稳态概率的迭代计算过程。将状态转移矩阵P循环与自身相乘，若连续两次乘积之差的矩阵2-范数小于给定的收敛精度，则认为此时的P的幂值为稳态概率矩阵P *。
Figure PCTCN2019075547-appb-000014
由于各个分析元素的MTBF和MTTR都是无记忆的独立过程且均值恒定，因此能够通过抽样估计故障信道数量一定时发生分区故障且不满足一致性或可用性的概率。算法2描述了单一网络拓扑结构下系统的分区容忍概率计算过程。对于稳态时系统可能处于的各种状态，分别采样N次，估计其发生分区故障且不满足一致性或可用性的概率，再根据全概率公式计算系统的分区容忍概率。
Figure PCTCN2019075547-appb-000015
最小修复时间的定义为系统在发生某种故障时能够修复部分信道使得系统满足一致性和可用性所需的最小时间。算法3描述了单一网络拓扑结构下系统的平均最小修复时间计算过程。在算法2的基础上，对于每一个发生分区故障且不满足一致性或可用性实例，计算其最小修复时间，再乘以该实例在总的系统分区容忍问题中所占的权重，得到系统的平均最小修复时间。
Figure PCTCN2019075547-appb-000016
二、层级化网络拓扑结构的分区容忍概率和最小平均修复时间
在一个层级化的网络拓扑结构中，下级域节点在本域内共识生成区块后，将该区块传递至上级域节点继续高一级的共识。对于一个n级网络拓扑结构，将各个域按照(i 1i 2i 3…)的树形结构编号，如图2所示。
下级域的分区容忍性不仅受自身的网络拓扑结构影响，还与高层级域的分区容忍性有关。令
Figure PCTCN2019075547-appb-000017
表示各个域的分区容忍概率。则系统的分区容忍概率为
Figure PCTCN2019075547-appb-000018
同理，令
Figure PCTCN2019075547-appb-000019
表示各个域的平均最小修复时间。则系统的平均最小修复时间为
Figure PCTCN2019075547-appb-000020
以数字光缆系统为例，下面分别计算联盟链中的投票证明共识机制(Proof of Vote，PoV)采用超方形网络拓扑结构和全连接网络拓扑结构时的分区容忍概率和平均最小修复时间。
根据国家标准的规定，具有主备用系统自动倒换功能的数字光缆通信系统应满足表1所示的全年指标。故取参数对(λ，μ)∈{(4.5662×10 -4，4.1667×10 -2)，(2.7397×10 -4，6.9444×10 -2)，(3.8358×10 -5，4.9603×10 -1)，(2.5571×10 -5，7.4405×10 -1)}。
表1数字光缆通信系统可靠性指标
链路长度/km 5000 3000 420 280
双向全程故障次数 4 2.4 0.336 0.224
MTBF/h 2190 3650 26070 39107
φ/fit 456620 273970 38358 25570
MTTR/h 24 14.4 2.016 1.344
F/％ 0.274 0.164 0.023 0.015
A/％ 99.726 99.836 99.977 99.985
多维超方形和多点全连接两种网络拓扑结构的资源开销如表2所示。
表2多维超方形和多点全连接网络拓扑结构的资源开销
Figure PCTCN2019075547-appb-000021
在PoV共识中，
Figure PCTCN2019075547-appb-000022
其分区容忍概率和平均最小修复时间的计算结果，如图3-图6所示。
继续考虑以图7-图10为例的4种层级化网络拓扑结构。图7给出了一种本方法的下边界情况，即顶级、二级和三级域的拓扑结构均为2维超方形；图8给出了一种完全对称的3级拓扑构造方法，顶级、二级和三级域的拓扑结构均为3维超方形；图9给出了一种半对称的2级拓扑构造方法，同级域间的拓扑结构相同，但顶级域的拓扑结构为4维超方形，二级域的拓扑结构则为3维超方形；图10给出了一种不对称的2级拓扑构造方法， 上级和下级域、同级域间的拓扑结构均不同，具体地，顶级域采用4维超方形结构，同时分别有4、8、4个二级域采用4维超方形、3维超方形和7点全连接结构。
假设图7-图10中拓扑的顶级、二级和三级链路长度分别为5000km、3000km和420km。利用图3-图6的多维超方形和多点全连接的分区容忍性计算结果，进一步计算图7-图10中的4种层级化网络拓扑结构的分区容忍概率和平均最小修复时间分别为：
(1)下边界情况
p＝1-[(1-p 1)+p 1*(1-p 11)*4+p 1*p 11*(1-p 111)*4*4]≈1-4×10 -4/h，即大约每3个月会发生一次分区失效故障。
t＝[t 1*(1-p 1)+t 11*p 1*(1-p 11)*4+t 111*p 1*p 11*(1-p 111)*4*4]/(1-p)≈21h，即发生分区失效故障后的平均最小修复时间大约为21个小时。
(2)完全对称的3级拓扑结构
p＝1-[(1-p 1)+p 1*(1-p 11)*8+p 1*p 11*(1-p 111)*8*8]≈1-5×10 -8/h，即大约每2,283年会发生一次分区失效故障。
t＝[t 1*(1-p 1)+t 11*p 1*(1-p 11)*8+t 111*p 1*p 11*(1-p 111)*8*8]/(1-p)≈23h，即发生分区失效故障后的平均最小修复时间大约为23个小时。
(3)半对称的2级拓扑结构
p＝1-[(1-p 1)+p 1*(1-p 11)*16]≈1-1×10 -8，即大约每11,416年会发生一次分区失效故障。
t＝[t 1*(1-p 1)+t 11*p 1*(1-p 11)*16]/(1-p)≈14h，即发生分区失效故障后的平均最小修复时间大约为14个小时。
(4)不对称的2级拓扑结构
p＝1-[(1-p 1)+p 1*(1-p 11)*4+p 1*(1-p 12)*8+p 1*(1-p 13)*4]≈1-6×10 -9，即大约每19,026年会发生一次分区失效故障。
t＝[t 1*(1-p 1)+t 11*p 1*(1-p 11)*4+t 12*p 1*(1-p 12)*8+t 13*p 1*(1-p 13)*4]/(1-p)≈14h，即发生分区失效故障后的平均最小修复时间大约为14个小时。
本发明的另一目的在于提供一种联盟链共识下满足分区容忍性的拓扑构造系统，所述拓扑构造系统包括
结合模块，用于将联盟链共识机制与网络拓扑结构相结合使联盟链共识在概率上满足分区容忍性；
收敛模块，用于将系统的分区容忍性抽象为一类可收敛的Markov过 程并获取系统的稳态概率；
抽样估计模块，用于估算故障信道数量一定时发生分区故障且不满足一致性或可用性的概率及最小修复时间，得到系统的分区容忍概率及平均最小修复时间；
构建网络模块，用于根据得到的分区容忍概率及平均最小修复时间分析不同网络拓扑结构下的资源开销和分区容忍性，为不同需求的联盟链共识构造规模适合、分区容忍性高的网络拓扑结构。
所述收敛模块中Markov过程收敛于一个独立初始分布的稳态分布，在单一网络拓扑结构下获取系统的稳态概率包括
循环相乘单元，用于将状态转移矩阵P循环与自身相乘；
判断单元，用于判断连续两次乘积之差的矩阵2-范数是否小于设定的收敛精度，若小于，则认为此时的P的幂值为稳态概率矩阵P *，若不小于，则返回循环相乘单元。
所述抽样估计模块中各个分析元素的MTBF和MTTR都是无记忆的独立过程且均值恒定；在单一网络拓扑结构下获取系统的分区容忍概率包括
采用单元，用于对于稳态系统的每个可能状态分别抽样N次；
估计单元，用于估计每个状态下发生分区故障且不满足一致性或可用性的概率；
计算单元，用于再根据全概率公式计算系统的分区容忍概率，全概率公式为：
Figure PCTCN2019075547-appb-000023
l表示信道总数，i表示稳态系统中有且仅有i条信道处于故障状态。
在单一网络拓扑结构下获取系统的平均最小修复时间包括
计算最小修复时间单元，用于对每一个发生分区故障且不满足一致性或可用性的样本计算最小修复时间；
计算平均最小修复时间单元，用于乘以该样本在总系统分区容忍问题中所占的权重，得到系统的平均最小修复时间。
在层级化网络拓扑结构中，根据共识的过程，下级域的分区容忍不仅受自身的网络拓扑结构影响，还与高层级域的分区容忍性有关；系统的分区容忍概率为
Figure PCTCN2019075547-appb-000024
Figure PCTCN2019075547-appb-000025
系统的平均最小修复时间为
Figure PCTCN2019075547-appb-000026
Figure PCTCN2019075547-appb-000027
其中，
Figure PCTCN2019075547-appb-000028
表示各个域的分区容忍概率，
Figure PCTCN2019075547-appb-000029
表示各个域的平均最小修复时间。
以上所述仅为本发明的较佳实施例而已，并不用以限制本发明，凡在本发明的精神和原则之内所作的任何修改、等同替换和改进等，均应包含 在本发明的保护范围之内。

Claims (10)

  1. 一种联盟链共识下满足分区容忍性的拓扑构造方法，其特征在于，所述拓扑构造方法包括以下步骤：
    S1、将联盟链共识机制与网络拓扑结构相结合使联盟链共识在概率上满足分区容忍性；
    S2、将系统的分区容忍性抽象为一类可收敛的Markov过程并获取系统的稳态概率；
    S3、估算故障信道数量一定时发生分区故障且不满足一致性或可用性的概率及最小修复时间，得到系统的分区容忍概率及平均最小修复时间；
    S4、根据得到的分区容忍概率及平均最小修复时间分析不同网络拓扑结构下的资源开销和分区容忍性，为不同需求的联盟链共识构造规模适合、分区容忍性高的网络拓扑结构。
  2. 根据权利要求1所述的联盟链共识下满足分区容忍性的拓扑构造方法，其特征在于，所述步骤S2中Markov过程收敛于一个独立初始分布的稳态分布，在单一网络拓扑结构下获取系统的稳态概率包括以下步骤：
    S21、将状态转移矩阵P循环与自身相乘；
    S22、判断连续两次乘积之差的矩阵2-范数是否小于设定的收敛精度，若小于，则认为此时的P的幂值为稳态概率矩阵P *，若不小于，则返回步骤S21。
  3. 根据权利要求2所述的联盟链共识下满足分区容忍性的拓扑构造方法，其特征在于，所述步骤S3中各个分析元素的MTBF和MTTR都是无 记忆的独立过程且均值恒定；在单一网络拓扑结构下获取系统的分区容忍概率包括以下步骤：
    S311、对于稳态系统的每个可能状态分别抽样N次；
    S312、估计每个状态下发生分区故障且不满足一致性或可用性的概率；
    S313、再根据全概率公式计算系统的分区容忍概率，全概率公式为：
    Figure PCTCN2019075547-appb-100001
    l表示信道总数，i表示稳态系统中有且仅有i条信道处于故障状态。
  4. 根据权利要求3所述的联盟链共识下满足分区容忍性的拓扑构造方法，其特征在于，在单一网络拓扑结构下获取系统的平均最小修复时间包括以下步骤：
    S321、对每一个发生分区故障且不满足一致性或可用性的样本计算最小修复时间；
    S322、乘以该样本在总系统分区容忍问题中所占的权重，得到系统的平均最小修复时间。
  5. 根据权利要求1-4任一项所述的联盟链共识下满足分区容忍性的拓扑构造方法，其特征在于，在层级化网络拓扑结构中，根据共识的过程，下级域的分区容忍不仅受自身的网络拓扑结构影响，还与高层级域的分区容忍性有关；系统的分区容忍概率为
    Figure PCTCN2019075547-appb-100002
    系统 的平均最小修复时间为
    Figure PCTCN2019075547-appb-100003
    其中，
    Figure PCTCN2019075547-appb-100004
    表示各个域的分区容忍概率，
    Figure PCTCN2019075547-appb-100005
    表示各个域的平均最小修复时间。
  6. 一种联盟链共识下满足分区容忍性的拓扑构造系统，其特征在于，所述拓扑构造系统包括
    结合模块，用于将联盟链共识机制与网络拓扑结构相结合使联盟链共识在概率上满足分区容忍性；
    收敛模块，用于将系统的分区容忍性抽象为一类可收敛的Markov过程并获取系统的稳态概率；
    抽样估计模块，用于估算故障信道数量一定时发生分区故障且不满足一致性或可用性的概率及最小修复时间，得到系统的分区容忍概率及平均最小修复时间；
    构建网络模块，用于根据得到的分区容忍概率及平均最小修复时间分析不同网络拓扑结构下的资源开销和分区容忍性，为不同需求的联盟链共识构造规模适合、分区容忍性高的网络拓扑结构。
  7. 根据权利要求6所述的联盟链共识下满足分区容忍性的拓扑构造系统，其特征在于，所述收敛模块中Markov过程收敛于一个独立初始分布的稳态分布，在单一网络拓扑结构下获取系统的稳态概率包括
    循环相乘单元，用于将状态转移矩阵P循环与自身相乘；
    判断单元，用于判断连续两次乘积之差的矩阵2-范数是否小于设定的收敛精度，若小于，则认为此时的P的幂值为稳态概率矩阵P *，若不小于，则返回循环相乘单元。
  8. 根据权利要求7所述的联盟链共识下满足分区容忍性的拓扑构造系统，其特征在于，所述抽样估计模块中各个分析元素的MTBF和MTTR都是无记忆的独立过程且均值恒定；在单一网络拓扑结构下获取系统的分区容忍概率包括
    抽样单元，用于对于稳态系统的每个可能状态分别抽样N次；
    估计单元，用于估计每个状态下发生分区故障且不满足一致性或可用性的概率；
    计算单元，用于再根据全概率公式计算系统的分区容忍概率，全概率公式为：
    Figure PCTCN2019075547-appb-100006
    l表示信道总数，i表示稳态系统中有且仅有i条信道处于故障状态。
  9. 根据权利要求8所述的联盟链共识下满足分区容忍性的拓扑构造方法，其特征在于，在单一网络拓扑结构下获取系统的平均最小修复时间包括
    计算最小修复时间单元，用于对每一个发生分区故障且不满足一致性或可用性的样本计算最小修复时间；
    计算平均最小修复时间单元，用于乘以该样本在总系统分区容忍问题中所占的权重，得到系统的平均最小修复时间。
  10. 根据权利要求1-4任一项所述的联盟链共识下满足分区容忍性的拓扑构造方法，其特征在于，在层级化网络拓扑结构中，根据共识的过程，下级域的分区容忍不仅受自身的网络拓扑结构影响，还与高层级域的分区容忍性有关；系统的分区容忍概率为
    Figure PCTCN2019075547-appb-100007
    系统的平均最小修复时间为
    Figure PCTCN2019075547-appb-100008
    其中，
    Figure PCTCN2019075547-appb-100009
    表示各个域的分区容忍概率，
    Figure PCTCN2019075547-appb-100010
    表示各个域的平均最小修复时间。
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