Seer: Accelerating Blockchain Transaction Execution by Fine-Grained Branch Prediction

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Abstract

Increasingly popular decentralized applications (dApps) with com-Increasingly popular decentralized applications (dApps) with complex application logic incur significant overhead for executing smart contract transactions, which greatly limits public blockchain perfor-contract transactions, which greatly limits public blockchain performance. Pre-executing transactions off the critical path can mitigate substantial I/O and computation costs during execution. However, pre-execution does not yield any state transitions, rendering the sys-pre-execution does not yield any state transitions, rendering the system state inconsistent with actual execution. This inconsistency can lead to deviations in pre-execution paths when processing smart contracts with multiple state-related branches, thus diminishing pre-execution effectiveness. In this paper, we develop Seer, a novel public blockchain execution engine that incorporates fine-grained branch prediction to fully exploit pre-execution effectiveness. Seer predicts state-related branches using a two-level prediction ap-predicts state-related branches using a two-level prediction approach, reducing inconsistent execution paths more efficiently than executing all possible branches. To enable effective reuse of pre-executing all possible branches. To enable effective reuse of preexecution results, Seer employs checkpoint-based fast-path execu-execution results, Seer employs checkpoint-based fast-path execution, enhancing transaction execution for both successful and unsuc-tion, enhancing transaction execution for both successful and unsuccessful predictions. Evaluations with realistic blockchain workloads demonstrate that Seer delivers an average of 27.7 × transaction-level speedup and an overall 20.6 × speedup in the execution phase over vanilla Ethereum, outperforming existing blockchain execution acceleration solutions.