Ethereum Beacon Chain’s Finality Issues led to 253 Missed Blocks in 2 Days: Glassnode

The Beacon Chain – which serves as the consensus layer for the Ethereum network – experienced technical issues on two separate occasions last week, causing it to stop finalizing blocks. While blocks were being proposed, they were not validated during a 25-minute window.

The two incidents were recorded on May 11th and 12th when more than 60% of the validators stopped performing their duties, thereby causing a loss in Finality.

Loss in Finality

According to Glassnode, “Finality” essentially refers to the state where a supermajority of validators  – two-thirds of the total stake – have attested to the final state of the blockchain, guaranteeing that a block and its processed transactions cannot be modified or eliminated from the blockchain.

The Beacon chain’s performance degraded last week as nearly 60% of validators were offline and absent from carrying out their consensus responsibilities. The analytic firm noted that around 3.68% of daily slots were missed, and 253 blocks were not proposed on time. This remains substantially lower than the 658 blocks missed across the Shapella upgrade.

Glassnode further observed that some consensus layer clients encountered older attestations and were forced to load up older states for verification while trying to handle new incoming онес simultaneously. This subsequently caused these systems to “overheat and malfunction.”

Not all clients were affected due to a difference in design approach. As a result, the validators running these were able to process transactions and produce blocks.

The affected validators in both cases, however, came back online within 20 minutes and an hour, respectively. The participation rate readily climbed back to over 98%.

During the two losses in Finality, no end-users on the Ethereum mainnet were impacted and were able to transact on the network owing to client diversity. But, the second one resulted in the first-ever Inactivity Leak, which is an emergency state utilized to recover Finality on the Beacon Chain. In such a case, the inactive validators are penalized until they are diluted out of the chain or start participating.

On a more technical level, some consensus layer clients encountered older attestations and were forced to load up older states for verification, whilst simultaneously trying to handle new incoming attestations, which eventually caused these systems to overheat and malfunction.… pic.twitter.com/qST8kvUkOc

— glassnode (@glassnode) May 14, 2023

Aftermath

In response to the issue, the developers of the Ethereum core released patches for Prysm Labs and Teku clients. In a statement, an Ethereum consultant said the issue with Finality “appears to have been caused by high load on some of the Consensus Layers clients, which in turn was caused by an exceptional scenario.”

The two clients released upgrades that implement optimizations to ward off beacon nodes from consuming excessive resources.

The finality issues follow increased activity and staking rewards rates on Ethereum due to the memecoin resurgence that triggered a massive jump in gas consumption on the network, with fees hitting a 12-month high.