Modelig And Performance Research Of Blockchain System Based On Discrete Time Gated Service

With the rise of bitcoin and other digital currencies,blockchain technology,as the core technology of cryptographic digital currency,has shown explosive growth in its research and application.And the performance research of the blockchain system has also become a hot topic.Based on the confirmation process of transactions in blockchain system,the modeling,the performance evaluation and the performance optimization of blockchain system are studied in the discrete time domain with the theory of non-exhaustive random service.Firstly,for the blockchain system with a light-load traffic and few network nodes,considering the very short verification time of empty blcocks,a zero-length empty block verification mechanism is introduced.Combining gated service and batch service,a discrete-time non-exhaustive multi-vacation queue with batch service is established.By using an embedding Markov chain method and regeneration cycle approach,the expression of the average confirmation time of transactions is given.Secondly,for the blockchain system with a light-load traffic and a large number of network nodes,cnsidering the verification time of empty blocks,a non-zero length empty block verification mechanism is introduced.Combining gated service and batch service,a discrete-time non-exhaustive single-vacation queue with batch service is established.By analyzing the model,the expressions of the system performance indicators such as the average confirmation time of the transaction in the blockchain system and the system empty block rate are given.Thirdly,for the blockchain system with a heavy-load traffic,a new block verification mechanism with grouping is introduced based on the non-zero length empty block verification mechanism.Combining gated service and group-batch service,a discrete-time non-exhaustive single-vacation queue is established.By using the renewal process method,the maximum and minimum average confirmation time of the transactions in the blockchain system are given.Finally,by conducting numerical experiments and simulation experiments to investigate the effects of each parameter in each queue on the blockchain system performance.For the light-load blockchain system with the zero-length empty block verification mechanism,the Nash equilibrium behavior and the social optimal behavior of transactions are studied,and a reasonable charging scheme is proposed to make the system achieve social optimal.For the light-load blockchain system with the non-zero length empty block verification mechanism,and the heavy-load blockchain system,based on the average confirmation time of the transaction in the blockchain system and the system empty block rate,a cost function is constructed,and the setting scheme of the optimal mining rate of the blockchain system is given.