| Blockchain as a new decentralized distributed computing paradigm.On account of the properties of multi-party formulation of trust,security,autonomy,and sovereignty without third parties,it has earned rising attention and applications.Initially,blockchain was only applied in the digital currency industry.With its evolution,the adoption of blockchain has progressively expanded to various industries such as finance,trade,credit investigation,and copyright protection,etc.Compared with the public blockchain,the consortium blockchain has more eminent transaction performance and is more manageable to be supervised.Accordingly,the consortium blockchain is promoted by numerous industry organizations.The utilization scenarios of it have been exceedingly expanded in various industry fields.The consortium blockchain has encountered multiple difficulties and trials in the advancement.Among these hurdles,the bottleneck predicament that most affects its further growth is the scalability of the consortium blockchain.The scalability issue comprises three aspects.The first one is performance scalability.Specifically,though the transaction performance of the consortium blockchain is significantly better than that of public blockchain such as Bitcoin,it still cannot satisfy some application scenarios which demand high concurrency and high-rate performances.The second aspect is the storage scalability issue.For all nodes in the entire network property and manage the same block data,it is impracticable to lessen storage overhead by appending nodes.With the continuous germination of block data,the storage pressure of nodes will inevitably become much more onerous.The third aspect is the node dynamic scalability issue.The consortium blockchain has mechanisms of admittance and administration.Yet,in the Byzantine fault-tolerant consensus algorithm,on which the alliance chain system is based,nodes are not able to dynamically enter or exit the consensus network.This assuredly restricted the dynamic scalability of the node scale.Consequently,this paper concentrates on the key technologies of the scalability of the consortium blockchain.The main work results of this paper are as follows:Firstly,this paper attempts to solve the low transaction performance difficulty to fulfill the requirements of several high-concurrency and high-rate application scenarios.From the aspect of distributed computing,this paper analyzes the performance expansion of the consortium blockchain,devises a scalable alliance chain construction,and proposes a distributed parallel computing model for the consortium blockchain.Through the functional partition for the consortium blockchain network and broader specific logical classification of the system nodes,the research has accomplished the detachment of computing and storage.Separating the transaction execution and verification could present a more fine-grained decomposition,which can be used to achieve the decoupling of transaction execution and verification.Manipulating dynamic grouping and parallel computing of nodes,the study promotes the parallelism of transaction execution,thereby promoting the overall transaction performance of the consortium blockchain system.Secondly,in terms of the storage scalability concern,the research introduced a package load balancing storage expansion model that stands on RS erasure codes.This model fixes and optimizes the full redundant storage mode of compound copies of the ledger data in the alliance chain.By arranging light nodes in the system,the model applies erasure codes to encode the block data files after segmentation.In this way,per light node could only be stored as part of the coded blocks.This efficiently lessens the storage burden of individual nodes and presents proper redundancy to recover the storage fault tolerance of the system.This scheme adopts the group storage mode and assures the overall storage load balance of the system through the device of the algorithm.Thirdly,the paper contributes a dynamic node enlargement scheme based on the recommendation mechanism after regarding the feeble dynamic scalability and the inability of consortium blockchain nodes to dynamically enter and exit the consensus network under the Byzantine fault-tolerant consensus mechanism.This purpose accomplishes nodes to dynamically join the network,and appends a node dynamic management protocol to the PBFT consensus mechanism.Without the call to pause and restart the system network,node dynamics can dynamically adjust the consensus state parameters of the entire network to succeed in entering and exiting the consensus network.This purpose could hugely enhance the dynamic scalability of consortium blockchain nodes.Sequentially,this paper promotes the Hyperledger Fabric architecture,composes and executes a digital copyright trading prototype system.Based on the copyright trading system,the research conducted laboratory tests on the research content.Experimental results confirm that compared with the primary Fabric architecture,the refined architecture has notable advances in transaction performance,storage performance,and node dynamic scalability. |
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