Solana sets Oct. 21 for Alpenglow’s 150ms finality target

Solana users will not need to change how they send transactions when Alpenglow is scheduled to activate on Oct. 21, but the upgrade aims to make transactions final much sooner. The Solana Foundation’s upgrade guide says the target is about 150 milliseconds, down from roughly 12.8 seconds today.

Faster finality could let merchants and other services rely sooner on a payment being settled.

Finality means the point at which a transaction can no longer be reversed. The upgrade changes how Solana’s validators agree on transactions; it does not change transaction execution, fees or the way wallets and apps work, according to the Foundation. The 150-millisecond figure is a target, and actual performance depends on network conditions.

What changes for Solana users when Alpenglow activates?

For most users, nothing needs to be installed or configured. The Foundation says wallets and apps will keep working as they do now, and transaction fees will remain unchanged. The potential difference is that a service waiting for stronger confirmation, such as a merchant or a bridge releasing funds on another blockchain, may be able to act sooner.

Alpenglow replaces TowerBFT, Solana’s current consensus system. Instead of recording validator votes as onchain transactions, the new system has validators send votes directly to each other and combine approvals into certificates. A block becomes final after one or two rounds of voting.

What must validators prepare before the switch?

Validators need to run software built on Agave 4.3.0 before epoch 1064 begins, which the Foundation estimates will start at about 15:00 UTC on Oct. 21. Agave, Jito-Solana and Harmonic Salsa are supported for the migration; Firedancer and Frankendancer operators must switch clients temporarily. The date and time are estimates because epoch timing can shift.

Operators also need at least 0.8 SOL above the rent-exempt minimum in their vote account to pay the Validator Admission Ticket fee. The Foundation says the fee is charged each epoch and pays for validator participation in the following epoch; an account that cannot pay will not vote or produce blocks in that next epoch. Under the current system, validators pay about 1 SOL per epoch in vote transaction fees, which Alpenglow removes.

Will Solana’s transaction counts change?

Yes: vote transactions will no longer appear in blocks, so reported transaction totals may drop even if user activity stays steady. As CoinDesk reported, dashboards and metrics that include validator votes may therefore look different after the switch. That change reflects what is counted, rather than necessarily a change in trading or payments.

The Foundation says the feature gate activates at the start of epoch 1064, but TowerBFT will continue for the first 5,000 slots, about 18 minutes, before Alpenglow takes over. Developers and data providers that read block streams or count transactions should check the upgrade guide for migration steps. Apps that only send transactions and read account state do not need to migrate.

Source material

• Solana Foundation’s upgrade guide — solana.com
• CoinDesk reported — coindesk.com