Резкое снижение активности валидаторов Ethereum после ошибок в консенсус-клиенте Prysm Translation: Headline: Sharp Decline in Ethereum Validator Activity Following Errors in Prysm Consensus Client

Soon after the deployment of Fusaka, a failure occurred in the popular consensus client Prysm, disrupting a portion of Ethereum validators.

A bug was identified in client version v7.0.0, causing outdated blockchain states to be unnecessarily generated when processing old confirmations.

As clarified by lead developer Terence Cao, the issue hindered the proper operation of nodes utilizing this client. Experts provided a temporary workaround to disable the problematic feature.

Nevertheless, during epoch 411,448, key network metrics saw a significant decline. Only 75% of nodes were signing valid block headers, while participation in the consensus dropped to 74.7%. Ethereum was on the verge of a full-scale failure, as less than nine percentage points remained before block finalization completely halted.

As of the current state (epoch 411,760), network performance has stabilized, with metrics nearly returning to pre-crisis levels.

Prior to the incident, these values consistently exceeded 99%.

The decrease in consensus participation roughly corresponds to the proportion of validators using the Prysm client, which was evaluated at 22.71% on December 3, but is now at 15.65%.

According to Ethereum’s consensus rules, the network loses finalization if validator voting participation falls below a critical threshold—two-thirds of all staked Ether.

In such circumstances, new blocks may be created, but the chain ceases to be irreversibly confirmed, greatly increasing the risk of transaction history reorganization. A loss of finalization would trigger a cascading failure throughout the entire ecosystem. Potential consequences could include:

This scenario is not merely hypothetical. In May 2023, Ethereum experienced finalization failures—twice in a single day—due to data processing errors in the Prysm and Teku clients.

The current incident appears relatively localized, but historically, the risk has been significantly higher. In the fall of 2021, Prysm controlled over 66% of nodes, meaning a bug in it could have paralyzed the entire network.

By January 2022, its share had risen to 68.1%, leaving the network in a vulnerable state.

Despite some progress, Ethereum is still far from a secure client distribution. A critical threshold for any client is considered to be 33%. Currently, Lighthouse dominates with a share of 52.55%.

«We narrowly avoided disaster by sheer luck. Had the bug occurred in Lighthouse, the network could have lost finalization,» commented Ethereum expert Anthony Sassano.

Recall that in early September, a failure occurred in the execution client Reth from Paradigm, which halted synchronization of nodes using that software.