Anza is scheduled to launch the Solana Alpenglow mainnet upgrade on October 21

The Solana development team Anza has scheduled the migration of Alpenglow's mainnet Beta to approximately 10:50 AM Eastern Time on October 21 (Wednesday), at which point the new consensus system will replace TowerBFT, aiming to reduce the final confirmation time for transactions to about 150 milliseconds. The Solana Foundation's upgrade guide indicates that the final confirmation time under TowerBFT is about 12.8 seconds. Final confirmation refers to the point in time when a transaction can no longer be rolled back, rather than the block interval.

Alpenglow's Votor voting protocol no longer submits votes as on-chain transactions; instead, messages are sent directly between validators and aggregated into certificates, allowing blocks to be finally confirmed after one to two rounds of voting; removing voting transactions from blocks also frees up block space for users, while the execution and fees for user transactions remain unchanged. This upgrade had previously completed testing network and development network migration in September, and the mainnet functionality switch has not yet been activated. According to Anza's activation policy, the new version of the software must be adopted by 95% of the staked amount for two epochs before activation on the mainnet.

The migration plan separates the activation of the functionality switch from the handover itself: the functionality switch is activated at the epoch boundary, and after 5,000 slots, blocks will pause carrying user transactions and will only contain votes. Validators will then establish the Alpenglow genesis certificate supported by 82% of the staked amount, roll back blocks that only contain votes, and then restore user transactions with Votor. Anza expects the handover to take several hundred milliseconds.