Solana Targets 150ms Finality With Alpenglow Upgrade

Solana replaced TowerBFT with Alpenglow on its mainnet on October 21, in its most significant consensus change since launch. The new protocol targets a finality close to 150 milliseconds, compared to about 12.8 seconds previously, but part of the planned architecture is still to be deployed. In Brief Solana activated Alpenglow on October 21, replacing TowerBFT on its mainnet. The new consensus targets a finality of 150 milliseconds, compared to 12.8 seconds previously. The transition occurred without a network-wide outage, with participation from 654 validators. The Votor mechanism speeds block validation through new voting procedures and BLS signatures. Alpenglow promises faster final transactions and better fault tolerance. Alpenglow Replaces TowerBFT on the Mainnet The activation began at the start of epoch 1064. However, the network retained TowerBFT for the first 5000 slots of this epoch, about 18 minutes, to prepare the transition to the new system. Your 1st cryptos with SwissborgThis link uses an affiliate program. The transition completed at slot 459653000. The validators then formed the cryptographic certificate marking the birth of the Alpenglow consensus. Anza, the lead developer of the Agave client, described this operation as the “greatest upgrade in Solana’s history”. The key elements of the activation illustrate the magnitude of the change : Alpenglow replaces the TowerBFT consensus used since Solana’s inception ; The targeted finality goes from 12.8 seconds to about 150 milliseconds ; 654 validators participated in the transition ; The switch from one consensus to the other lasted about 900 milliseconds ; Validator votes are no longer recorded as on-chain transactions ; BLS signatures allow multiple votes to be aggregated into a single certificate ; Each admitted validator must pay a ticket of 0.8 SOL per epoch. The transfer occurred without a full network halt. During the critical phase, blocks temporarily stopped including user transactions and carried only the necessary votes. This precaution was to allow a rollback without invalidating a user-signed operation. Once the genesis certificate was formed, nodes handed the consensus over to the new Votor algorithm. Transactions then resumed under the Alpenglow regime. Votor Dramatically Reduces Final Confirmation Delay The consensus allows validators to agree on the order of transactions and when a block can no longer be reverted. With TowerBFT, Solana produced blocks quickly, but their full finality required about 12.8 seconds. Votor uses two voting procedures in parallel. The first can finalize a block in one round when 80% of tokens staked staking respond. The second can conclude after two rounds with 60% participation. The protocol adopts the path that finishes first. Votes are no longer recorded as ordinary transactions. Validators exchange signed messages directly via the BLS system. Multiple signatures can then be aggregated into a compact certificate, freeing block space for user operations.