Solana activates Alpenglow with 150ms finality target

Solana activated Anza’s Alpenglow consensus upgrade on mainnet on Oct. 21, replacing TowerBFT and targeting transaction finality in about 150 milliseconds, according to Anza’s announcement. The handoff took place at slot 459,653,000, Anza said; the target compares with about 12.8 seconds under the previous system.

How does Alpenglow aim to cut finality?

Alpenglow’s Votor protocol lets validators send votes directly to one another and combine them into certificates. A block can become final after one or two rounds of voting, according to the Solana Foundation’s upgrade guide.

Under TowerBFT, validators submitted votes as transactions, which accumulated over 32 slots. The new system removes those vote transactions from blocks. Solana’s transaction execution, programs and fees remain unchanged, the Foundation said.

Does 150 milliseconds describe every transaction?

No. The Foundation describes roughly 150 milliseconds as Alpenglow’s target, and says it is the time to finality, not the time between blocks. The target is not a guarantee for every transaction or network condition.

Finality is the point at which a transaction can no longer be reversed. Faster finality could let services treat payments or exchange deposits as settled sooner, but the announcement does not establish a universal user-facing settlement time.

What comes next for Solana’s upgrade?

Alpenglow’s first phase, Votor, is live. The second phase, Rotor, is planned to replace Turbine, Solana’s block-data distribution protocol, but the Foundation says it has no scheduled release date.

The mainnet activation and protocol change are confirmed. How consistently the network will deliver the 150-millisecond target in live conditions remains to be established; Rotor’s timing is also unconfirmed.

Source material

• Anza’s announcement — prnewswire.com
• Solana Foundation’s upgrade guide — solana.com