Bug Takes Out 8% Ethereum Validators, More Damage Expected – Bankless Times

A bug in Ethereum's Nethermind, a piece of software that validators use to interact with the Ethereum Mainnet, took down 8% of those. The incident revived the debate on "client diversity," which CoinDesk reported on.
Experts pointed out that if Geth had gone down – Geth is the Mainnet’s most popular executor – things could have been really bad. Geth can be a single point of failure, meaning that Ethereum would stop operating if Geth went down.
The whole Nethermind software was taken down, which supports around 8% of the validators that run Ethereum. Sunday’s incident was critical enough to justify a decision to take the affected validators offline. The Mainnet remained up and running despite the issue, and the worst impact was small financial penalties for some validators on Nethermind.
Of more concern is the fact that an almost identical incident preceded the Nethermind one. In January, a bug took out Besu, a piece of software powering around 5% of Ethereum's validators. The incidents sparked a fierce discussion on X of the problem with client diversity. The fact that Ethereum relies on little client software makes it less resilient.
Currently, Geth powers around 85% of Ethereum's validators. Its dominance could have severe consequences if issues with its programming arise.
Geth has never suffered from a bug like the ones that hit Besu and Nethermind, but it’s not immune to such. A glitch could halt the Mainnet completely, making it impossible for validators to add new blocks.
Ethereum is programmed to punish validators that break the blockchain’s rules or go offline, which means it could hold Geth-based validators financially liable if an incident occurs. If the issue is hard to patch, the penalties could get enormous.

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