Shapella Successfully deployed, closing the PoS loop for Ethereum

Shapella upgrade, Prysm bug, Lighthouse fix, Ethereum network health at the time of upgrade, FAQ and more!

Shapella Successfully deployed, closing the PoS loop for Ethereum

Another exciting Ethereum upgrade - Shapella is live on the mainnet on April 12, 2023 at epoch 194048. Activating the staked ETH Withdrawal, this closes the loop of Proof of Stake Ethereum blockchain.

Shapella is a combination of two terms: Shanghai and Capella. Shanghai refers to the fork on the execution client side, while Capella represents the upgrade on the consensus layer client side. Let's take a look at the network health report as shared on the developers call today.

"Great Work Everyone on Shapella! Network Transitioned Successfully" ~ Tim Beiko

Successful Shapella

Tim Beiko praised the successful transition of the Shapella network. Danny Ryan noted that more validators were attesting and not proposing, indicating that nodes were up and running, following the chain, and voting. The network experienced a higher number of missed slots right after the fork, with 40,000 BLS change operations broadcast, causing high CPU loads. Everything is normal and smooth now.

Lighthouse Fix

The Lighthouse bug involved excessive CPU usage when the network experienced a combination of missed blocks and a high volume of voluntary exits. This issue occurred after the Shapella upgrade on April 12th UTC. The excessive CPU usage could potentially interfere with normal node operations, such as staking, and impact the overall performance of the network. To address the excessive CPU usage issue, a high-priority hotfix release, 4.0.2-rc.0, was rolled out for mainnet Lighthouse users.

The hotfix specifically targets the Beacon Node and does not require any updates for the Validator Client from v4.0.1 (or v4.0.1-rc.0). The purpose is to alleviate the high CPU usage issue and ensure that normal node operations can continue without disruption. Mainnet users are strongly recommended to update to this release to prevent the high CPU usage from affecting their staking operations and overall node performance. The hotfix has not yet been applied to the unstable or stable branches.

Prysm Bug

The Prysm bug occurred during the Shapella upgrade, where relays encountered failures in Prysm signatures with the error message "could not verify Capella payload signature." This issue was likely overlooked during testing on the testnet due to the low percentage of Prysm validators (1-2%), causing developers to miss the error. The bug resulted in a higher number of missed slots right after the fork.

Prysm 4.0.2 addresses the signature error by adding the bls-to-exec field when attempting to unblind a block in Capella. The block is then sent to the relayer via SubmitBlindedBlock. The Prysm team missed including the bls-to-exec object in the blind block itself, causing the relayer to get a signature verification error due to the different hash tree root.

Prysm 4.0.2

Prysm 4.0.2 not only fixes the critical bug related to mev-boost/relayer, but also includes miscellaneous optimizations and fixes. The release revamps the next slot cache to be more performant across edge case re-org scenarios, helping to address the bad head attestation vote issue. Additionally, this release includes minor fixes that address a bug affecting certain large operators querying RPC endpoints. This bug caused unexpected behavior and may have impacted the performance of affected operators.

A post-mortem report describing the incident will be provided by the end of the week, explaining in detail what happened during the Shapella upgrade and the measures taken to address the situation.

Shapella FAQs

While the Ethereum community is excited, some people remain confused about the upcoming upgrade. The EtherWorld team has made their best effort to answer all common questions regarding the Shapella hard fork in our latest blog post.


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