Shapella Undergoes Mainnet Shadow Fork 2

Withdrawal MSF 2, Withdrawal Devnet 7, Zheijang Bugs, Sepolia Shapella Fork & Goerli Shapella Fork

Shapella Undergoes Mainnet Shadow Fork 2

Ethereum is gearing up for Shapella Network Upgrade. The upgrade, set to be implemented in early April 2023, will bring a major change to the Ethereum network with the activation of Beacon Chain Withdrawals. Ethereum's core developers have been continuously testing as the release date approaches. In this blog post, we'll look closely at the latest testing updates.

Withdrawal Mainnet Shadow Fork 2

Shapella Fork on Withdrawal Mainnet Shadow Fork 2 was successfully launched on March 3, 2023, and is performing well with all client combinations. To ensure the network's stability, developers also ran several rigorous scenario tests, such as taking the mock relay offline and triggering circuit breaker conditions of missing blocks in a row/epoch. These tests proved successful, as the circuit breaker was triggered as expected in clients with it implemented, and the network continued to finalize.

However, the developers did encounter one issue with a besu node and a worldstate problem. They are currently investigating and addressing this issue, and once it's resolved, they will deprecate the testnet.

Withdrawal Devnet 7

Withdrawal Devnet 7 was launched on February 14th. The Capella fork took place 48 hours later on February 16th, bringing together 600K validators, 300K BLS changes, and 100K exits, all in an effort to simulate worst-case scenarios.

This devnet is testing a wide range of functions, including deposits, exits, and withdrawals, all at the same time. To ensure thorough testing, developers are using approximately 120 nodes, and it is designed to follow mainnet specs.

Bugs: The Besu Client recently encountered a problem where it was creating bad blocks due to a misreporting of proposed bad blocks. The developers quickly identified the problem and deployed a fix to address the issue.

Zheijang Bugs

Marius VanDerWijden found a bug on Zheijang Testnet that showed up during full sync for empty blocks, i.e., a block with no transactions. According to him, the issue was that if a block body were empty, Geth wouldn't initialize it correctly. A quick fix is deployed by him.

Other clients also had experienced this issue except for Nethermind. Therefore, client Developers will also add Hive test for this case. Whole end-to-end MEV-Boost system was also running on Zhejiang Testnet. Furthermore, the Builder specs were also updated and merged.

Sepolia Shapella Fork

The Sepolia Shapella Fork was a success, with several BLS credential updates processed seamlessly during the fork. Although participation on the network dropped slightly due to unupgraded EL clients, the issue was resolved after these were updated, and participation levels quickly recovered.

As the validator set on Sepolia is small, only a single full withdrawal was tested, but partial withdrawals are processed automatically. Despite this successful testing, Nethermind reported a minor issue where they produced a small number of bad blocks. However, they are investigating the issue and have assured that it is not related to the Shanghai code.

Goerli Shapella Fork

On March 14th at 10:25pm UTC, client developers agreed to proceed with a Shapella fork on Goerli. The client releases and the announcement of the fork are expected to be made early next week. Additionally, Withdrawal Devnet 8 is also expected in the coming weeks.

The developers are taking no chances with the testing process, recognizing the importance of identifying and addressing any potential issues before the mainnet upgrade.

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