Blockumulus: A Scalable Framework for Smart Contracts on the Cloud
Blockumulus: A Scalable Framework for Smart Contracts on the Cloud
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DOI：
10.1109/icdcs51616.2021.00064
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发表时间：
2021-07
期刊：
影响因子：
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通讯作者：
Nikolay Ivanov;Qiben Yan;Qingyang Wang
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文献类型：
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作者：
Nikolay Ivanov;Qiben Yan;Qingyang Wang
公共区块链促进了去中心化交易和智能合约的日益普及，特别是在金融市场上。然而，公共区块链在交易吞吐量、存储可用性和计算能力方面表现出局限性。为了避免交易僵局，公共区块链征收高额费用和每个区块的资源限制，使得其难以适应不断增长的高交易需求。以前的研究致力于通过各种技术来提高区块链的可扩展性和性能，例如侧链，分片，安全的链下计算，通信网络优化和高效的共识协议。然而，这些方法尚未获得广泛采用，因为它们无法在事务吞吐量、存储和计算能力的可扩展性方面提供类似云的性能。在这项工作中，我们确定公共区块链可扩展性的主要障碍是其底层的非结构化P2P网络。我们进一步表明，集中式网络可以支持去中心化智能合约的部署。我们提出了一种实现可扩展去中心化的新方法：我们不是试图使区块链可扩展，而是通过使用以太坊智能合约将去中心化交付给已经可扩展的云。我们介绍了Blockumulus，这是一个框架，可以使用一种称为覆盖共识的新技术来部署分散的云智能合约环境。通过实验，我们证明了Blockumulus在所有三个方面都是可扩展的：计算，数据存储和事务吞吐量。除了消除当前的代码执行和存储限制外，Blockumulus在正常负载下提供了2到5秒的事务延迟。此外，我们的原型的压力测试显示，它能够在26秒内同时执行20，000笔交易，这与全球信用卡交易的平均吞吐量相当。
Public blockchains have spurred the growing popularity of decentralized transactions and smart contracts, especially on the financial market. However, public blockchains exhibit their limitations on the transaction throughput, storage availability, and compute capacity. To avoid transaction gridlock, public blockchains impose large fees and per-block resource limits, making it difficult to accommodate the ever-growing high transaction demand. Previous research endeavors to improve the scalability and performance of blockchain through various technologies, such as side-chaining, sharding, secured off-chain computation, communication network optimizations, and efficient consensus protocols. However, these approaches have not attained a widespread adoption due to their inability in delivering a cloud-like performance, in terms of the scalability in transaction throughput, storage, and compute capacity. In this work, we determine that the major obstacle to public blockchain scalability is their underlying unstructured P2P networks. We further show that a centralized network can support the deployment of decentralized smart contracts. We propose a novel approach for achieving scalable decentralization: instead of trying to make blockchain scalable, we deliver decentralization to already scalable cloud by using an Ethereum smart contract. We introduce Blockumulus, a framework that can deploy decentralized cloud smart contract environments using a novel technique called overlay consensus. Through experiments, we demonstrate that Blockumulus is scalable in all three dimensions: computation, data storage, and transaction throughput. Besides eliminating the current code execution and storage restrictions, Blockumulus delivers a transaction latency between 2 and 5 seconds under normal load. Moreover, the stress test of our prototype reveals the ability to execute 20,000 simultaneous transactions under 26 seconds, which is on par with the average throughput of worldwide credit card transactions.