Ethereum consensus layer client Prysm releases post-mortem report on the failure

Techub News reports that the Prysm team, an Ethereum consensus layer client, has released a post-mortem analysis report on the Fusaka mainnet outage. A network failure occurred in Prysm on December 4th. During the incident, almost all Prysm nodes experienced resource exhaustion when processing specific attestations, leading to an inability to respond to validator requests in a timely manner. The outage affected epochs 411439 to 411480, resulting in the loss of 248 blocks across 42 epochs, with a missing rate of 18.5%. The network participation rate dropped to a minimum of 75%, and validators lost approximately 382 ETH in attestation rewards.

The root cause was that Prysm beacon nodes received attestations, potentially from unsynchronized nodes, which referenced block roots from a previous round. To validate these attestations, Prysm attempted to reconstruct compatible states, leading to repeated processing of past round blocks and expensive recomputation of round transitions. The team temporarily resolved the issue by instructing users to use the --disable-last-epoch-target parameter. Subsequent versions v7.0.1 and v7.1.0 contain long-term fixes.