Efficient and Fair Scheduling Schemes for Enabling Priority Awareness in Blockchain Systems

Abstract

Priority scheduling techniques aim to schedule tasks with higher priority and tighter deadlines to be executed before other tasks. However, traditional blockchain systems do not work well with priority scheduling due to issues regarding consensus mechanisms, throughput, and scalability. In this work, we propose three transaction scheduling schemes which employ a fee-based model to differentiate priority levels of transactions and select transactions for validation and inclusion based on criteria other than the order of arrival. The Priority-Based Scheduling scheme focuses on the priority level of individual transactions, the Contract-Based Scheduling scheme emphasizes the satisfaction of more customer contracts, whereas the Latency-Based Scheduling scheme prioritizes transactions with closer deadlines when bursts of transactions overwhelm the blockchain network. We implement prototypes of our transaction scheduling schemes in a private Algorand-inspired simulation and evaluate their performance by testing them under scenarios representing different transaction distribution ratios. The results show that the three transaction scheduling schemes outperform the baseline in which no scheduling is applied, and each scheme performs best in the transaction distribution scenario it is designed to handle.