Polygon zkEVM 中断：深入揭示以太坊重组和同步问题

Polygon 的 zkEVM 网络因故障导致区块生产停止了 14 个小时，一周多后，开发人员发布了一份事后分析报告，解释说以太坊主网重组导致排序器接受带有已弃用时间戳的交易，从而导致了故障。

Polygon zkEVM Outage: Deep Dive into the Causes and Mitigation Measures

Polygon zkEVM 中断：深入探究原因和缓解措施

Over a week ago, Polygon Labs' Ethereum Layer 2 solution, Polygon zkEVM, experienced an unexpected outage that halted block production on the network for several hours. While the issue has since been resolved, the specific causes of the disruption remained shrouded in uncertainty until now. In a comprehensive post-mortem report, developers have shed light on the root causes of the event and outlined proactive steps taken to prevent future occurrences.

一周多前，Polygon Labs 的以太坊第 2 层解决方案 Polygon zkEVM 经历了意外中断，导致网络上的区块生产停止了几个小时。尽管该问题已得到解决，但造成中断的具体原因至今仍存在不确定性。在一份全面的事后分析报告中，开发人员阐明了该事件的根本原因，并概述了为防止未来再次发生而采取的积极措施。

Unraveling the Ethereum Reorg Trigger

揭开以太坊重组触发器的面纱

In their initial statements, Polygon Labs attributed the Polygon zkEVM outage to an Ethereum mainnet "reorg." A reorg, short for reorganization, occurs when a consensus disagreement over transaction ordering or validity arises, forcing the network to converge on a single version of the blockchain history, prioritizing the chain with the most computational work or stake backing it.

在最初的声明中，Polygon Labs 将 Polygon zkEVM 中断归因于以太坊主网“重组”。当对交易顺序或有效性出现共识分歧时，就会发生重组，迫使网络收敛于区块链历史的单一版本，优先考虑具有最多计算工作或支持它的权益的链。

According to the developers' post-mortem analysis, the Ethereum reorg in this instance resulted in the omission of a Polygon zkEVM deposit transaction. This critical change was not detected promptly by the Layer 2 chain's synchronizer, a component responsible for monitoring and relaying Layer 1 changes to Layer 2.

根据开发人员的事后分析，本次以太坊重组导致 Polygon zkEVM 存款交易被遗漏。第 2 层链的同步器（负责监视第 1 层更改并将其中继到第 2 层的组件）未能及时检测到这一关键更改。

Synchronization Failure and Transaction Rejection

同步失败和事务拒绝

The synchronizer's lapse in detecting the omitted deposit transaction had a cascading effect on the Polygon zkEVM sequencer, the component responsible for ordering and batching transactions for posting to the Ethereum mainnet. Unaware of the updated mainnet state, the sequencer continued to order transactions with timestamps that had become outdated on the mainnet.

同步器未能检测到遗漏的存款交易，这对 Polygon zkEVM 排序器（负责排序和批量交易以发布到以太坊主网的组件）产生了连锁效应。排序器不知道更新的主网状态，继续使用主网上已过时的时间戳对交易进行排序。

As a result, when these transactions were batched to the mainnet, they were rejected by the network due to their invalid timestamps. "Valid proofs for these transactions were generated, but the result of these transactions were no-operation, as if they were not there," the developers explained.

结果，当这些交易被批量发送到主网时，由于时间戳无效而被网络拒绝。 “这些交易的有效证明已经生成，但这些交易的结果是空操作，就好像它们不存在一样，”开发人员解释道。

Impact and Remediation

影响和补救

Approximately 4,000 transactions were affected by the outage. The developers attributed the prolonged 14-hour downtime to the efforts required to reconcile these affected transactions.

大约 4,000 笔交易受到中断影响。开发人员将长达 14 小时的停机时间归因于协调这些受影响的交易所需的努力。

In response to the incident, developers have released updated versions of the zkEVM node and prover components, including enhancements to the synchronizer to improve its ability to detect and respond to Layer 1 changes. Additionally, they have implemented an extra safeguard in the sequencer to cross-check transaction timestamps with the mainnet before batching them for submission.

为了应对这一事件，开发人员发布了 zkEVM 节点和证明者组件的更新版本，包括对同步器的增强，以提高其检测和响应第 1 层更改的能力。此外，他们在排序器中实施了额外的保护措施，以便在批量提交之前与主网交叉检查交易时间戳。

TVL Resilient, but Some Transactions May Require Further Attention

TVL 有弹性，但某些交易可能需要进一步关注

Polygon zkEVM's total value locked (TVL) appears to have remained largely unaffected by the outage. At the time of writing, L2Beat data indicates a slight increase from approximately $150 million to $153 million since the incident.

Polygon zkEVM 的总锁定值 (TVL) 似乎基本上没有受到中断的影响。截至撰写本文时，L2Beat 数据显示，自事件发生以来，销售额从约 1.5 亿美元略有增加至 1.53 亿美元。

However, Polygon Labs has cautioned that some of the affected transactions may still be pending processing. DApps that have identified affected transactions are encouraged to reach out to Polygon Labs for assistance.

然而，Polygon Labs 警告称，一些受影响的交易可能仍在等待处理。我们鼓励已发现受影响交易的 DApp 联系 Polygon Labs 寻求帮助。

Contextualizing the Outage

停电的具体情况

The Polygon zkEVM outage highlights the growing prevalence of network disruptions in the cryptocurrency space, particularly in the Ethereum Layer 2 ecosystem. In December 2023, Arbitrum, the largest Ethereum Layer 2 network by TVL, experienced an outage lasting over five hours due to a surge in network activity. Similarly, zkSync Era, the largest ZK-rollup by TVL, faced a four-hour outage in the same month.

Polygon zkEVM 中断凸显了加密货币领域网络中断日益普遍，特别是在以太坊第 2 层生态系统中。 2023 年 12 月，TVL 最大的以太坊第 2 层网络 Arbitrum 由于网络活动激增而经历了持续五个多小时的中断。同样，TVL 最大的 ZK-rollup zkSync Era 在同月也面临四个小时的宕机。

Importance of Post-Mortem Analysis

事后分析的重要性

This post-mortem report provides valuable insights into the causes and resolution of the Polygon zkEVM outage, addressing lingering uncertainties surrounding the incident. It underscores the importance of post-mortem analyses in enhancing the understanding of network disruptions, identifying areas for improvement, and building more resilient systems.

这份事后分析报告提供了有关 Polygon zkEVM 中断的原因和解决方案的宝贵见解，解决了围绕该事件的挥之不去的不确定性。它强调了事后分析在增强对网络中断的理解、确定需要改进的领域以及构建更具弹性的系统方面的重要性。