On May 11, an unidentified problem on the Ethereum Beacon Chain caused nearly half an hour of transaction finality.
At around 8:15pm UTC on May 11, some Ethereum core developers announced that the beacon chain was having problems confirming transactions. New blocks can be proposed, but an unknown issue prevents them from being finalized. A similar issue occurred on March 15, when low validator participation caused a delay in the Goerli testnet version of Ethereum’s “Shapella” upgrade, which was successfully implemented on mainnet on April 12.
The Beacon Chain is Ethereum's original proof-of-stake blockchain, first launched in 2020. On September 15, 2022, Ethereum's pre-existing proof-of-work chain "merged" with the beacon chain, finally completing the network's transition to a faster and greener proof-of-stake consensus mechanism. Twenty-five minutes later, the mainnet started finalizing blocks again, with ethereum core developer and Prysmatic Labs co-founder Preston Van Loon announcing that "certainty has been restored."
According to data from blockchain analytics provider Beaconcha.in, Ethereum witnessed a sharp drop in the number of proofs between epochs 200,552 and 200,554. An epoch is a period of 32 "slots" during which validators propose and attest blocks. An epoch typically lasts about 6 minutes and 24 seconds.
The cause of the problem is unclear, but ethereum developers say they are investigating the issue to prevent it from happening again. After the incident, pseudonymous ethereum advisor Superphiz pointed to “client diversity” as one of the main reasons why the loss of finality was so short-lived. However, he also pointed out that if no client had more than 33% control, the final loss could have been avoided entirely.
Client diversity refers to the number of software clients available to network validators, with greater diversity among clients meaning a more secure and robust network of validators.
