Ethereum Phases Out Holesky Testnet Amid Upgrade Challenges

Ethereum developers have announced plans to discontinue support for the Holesky testnet by September 2025. This decision follows a series of disruptions during the testing of the upcoming Pectra upgrade, prompting the introduction of a new testnet, Hoodi, to ensure smoother protocol transitions.

Key Takeaways

• Holesky testnet will be phased out by September 2025.

• The new Hoodi testnet will take over testing for the Pectra upgrade.

• Holesky faced significant issues that hindered its functionality during critical testing phases.

Background on Holesky Testnet

Launched in September 2023, Holesky has served as one of Ethereum's primary testnets, alongside Sepolia. It has been instrumental for developers in testing staking, infrastructure, and protocol upgrades. However, recent challenges have led to a reevaluation of its viability as a testing environment.

Issues Faced by Holesky

During the testing of the Pectra upgrade, Holesky encountered several critical issues:

• Execution Client Bugs: Major execution clients like Geth and Nethermind used incorrect deposit contract addresses, leading to bugs in the execution layer.

• Chain Splits: These bugs caused chain splits, which weakened the overall stability of the network.

• Validator Exit Congestion: The network experienced inactivity leaks, complicating the process of validator exits. It is estimated that it could take nearly a year to fully remove exited validators from the network.

Due to these issues, Holesky's utility for testing validator exits has been severely limited, prompting the need for a new testing environment.

Introduction of Hoodi Testnet

To address the shortcomings of Holesky, Ethereum developers have introduced the Hoodi testnet, which is set to activate on March 26, 2025. This new testnet aims to facilitate the testing of the Pectra upgrade and will serve as the primary environment for validator testing moving forward.

Transition Plans

• Holesky's Remaining Functionality: While Holesky will continue to support certain tests, such as deposits and consolidations, developers are advised against using it for validator exit testing due to the lengthy exit queue.

• Future of Testnets: The Ethereum Foundation has indicated that Holesky will remain operational for specific tests until its official discontinuation in September 2025. After this date, it may be repurposed for other testing scenarios, such as gas limit increases.

• Upcoming Changes: The Sepolia testnet is also scheduled for replacement in March 2026, with support ending by September 2026. Hoodi is expected to remain active until September 2028.

Conclusion

The decision to phase out the Holesky testnet reflects Ethereum's ongoing efforts to refine its testing infrastructure and ensure successful protocol upgrades. As the network prepares for the Pectra upgrade, the introduction of Hoodi represents a strategic move to enhance testing capabilities and maintain stability within the Ethereum ecosystem.

Sources

• Ethereum Developers Launch New Testnet for Pectra Upgrade After Earlier Setbacks, CoinDesk.

• Ethereum to end support for Holesky testnet by September 2025, CryptoSlate.

• Ethereum developers to end support for Holesky testnet in September, The Block.

• Ethereum to discontinue support for Holesky testnet in September, Crypto News.