Solana sets Alpenglow upgrade for October 21 with 150-millisecond finality target

Solana will activate its Alpenglow upgrade on October 21, replacing the TowerBFT consensus mechanism used since 2020 to target transaction finality in 150 milliseconds.

The network transition is scheduled for epoch 1064 and requires validators to run compatible Agave 4.3.0 software, as alternative validator clients will not support the initial migration.

The upgrade changes how validators reach agreement in order to make transactions irreversible more rapidly.