By Zhuolun Xiang, Siyuan Han, Zekun Li, and Alexander Spiegelman
Developer-Focused Summary
In this paper, Xiang, Han, Li, and Spiegelman explore how to engineer high-performance blockchains by applying pipelining principles from hardware, databases, and AI systems. Their core message is clear: to achieve both high throughput and low latency, blockchain design must move beyond sequential processing and embrace concurrent, parallelized architectures.
The Evolution of Blockchain Pipelines
Legacy Design: Sequential Execution
- Blocks are processed one at a time: proposal → execution → commit → repeat.
- Validators often sit idle, leading to poor resource utilization and high end-to-end latency.
Aptos: The Ford Factory of Blockchains
Aptos introduces a pipelined blockchain architecture, inspired by assembly lines:
- Asynchronous Execution & Commit (DIP-213): Consensus first, execution follows later.
- Pipelined Consensus (Jolteon): Start new consensus rounds before the current one finishes.
- Quorum Store: Offloads data dissemination from consensus to all validators, avoiding leader bottlenecks.
Dev Insight: Aptos turns validator resources into a parallel pipeline, maximizing throughput by running different stages of different blocks simultaneously.
Zaptos: Latency-Optimized Blockchain Design
Zaptos goes further—targeting sub-second latency without sacrificing throughput by embedding pipeline stages inside consensus:
- Optimistic Execution: Execute blocks as soon as they’re proposed.
- Optimistic Commit: Persist state pre-certification, revert if needed.
- Fast Certification: Begin certifying blocks before consensus completes.
Impact for Engineers:
- Pipeline latency becomes nearly equal to consensus latency.
- At 20K TPS, latency drops from 1.32s (Aptos) to 0.78s (Zaptos).
- Full node and validator workloads are parallelized and overlapped.
Benchmark Results
- Test Setup: 100 validators, 30 fullnodes, 10 cloud regions (Google Cloud)
- Latency: Zaptos maintains sub-second confirmation even under heavy load
- Throughput: Stable at 20,000 transactions per second (TPS)
Key Takeaways for Blockchain Developers
- Design for concurrency: Run consensus, execution, commit, and sync in parallel.
- Minimize latency with speculation: Start execution and commit optimistically.
- Avoid centralized bottlenecks: Use leaderless or horizontally-scaled data dissemination.
- Shadow latency inside consensus: Compress critical paths for real-time user experience.