The Ethereum network’s consensus layer, the Beacon Chain, faced technical problems twice last week, resulting in a loss of finality. During a 25-minute window, blocks were proposed but not validated in both incidences on May 11th and 12th. Over 60% of validators on the network stopped performing their duties, affecting the finality state. Finality is reached when a supermajority of validators attests to the final state of the blockchain. Glassnode reported that around 3.68% of daily slots were missed, and 253 blocks were not proposed on time.
Impact of the Incident
The degraded performance of the Beacon chain happened because nearly 60% of validators were offline, leading to Glassnode reporting that some consensus layer clients encountered older attestations and had to load older states while handling incoming ones simultaneously. This caused the systems to malfunction and overheat. Not all clients were impacted in the incident. Still, some running different designs were able to process transactions and produce blocks. In both cases, the affected validators came back online within 20 minutes and an hour, respectively, with participation rates quickly rising over 98%. However, during the second incident, the inactive validators were penalized until they were diluted out of the chain or participated again. Nonetheless, there was no visible impact on end-users transacting on the Ethereum mainnet due to client diversity.
In response to the problem, developers released patches to Prysm Labs and Teku clients to optimize their performance and prevent Beacon nodes from consuming excessive resources. An Ethereum consultant stated that the loss of finality appeared to be caused by high load on some Consensus Layers clients. This was caused by an exceptional scenario. The finality loss coincided with an increase in activity and staking rewards rates on Ethereum due to the memecoin resurgence, which resulted in a sharp rise in gas consumption, with fees reaching a 12-month high.