Solana schedules Alpenglow upgrade for Oct. 21

Solana is scheduled to begin activating Alpenglow on its main network on Oct. 21, replacing its current validator voting system in a bid to make transactions final in about 150 milliseconds. The Solana Foundation’s upgrade page says the change starts with epoch 1064 at about 15:00 UTC. Finality means a transaction can no longer be reversed.

The 150-millisecond figure is a target, not a confirmed measure of mainnet performance. The Foundation says the current system takes about 12.8 seconds to finalize a transaction. Alpenglow changes how validators agree that a block is final; it does not change how transactions execute.

How will Alpenglow change validator voting?

Validators will send votes directly to one another and combine enough approvals into certificates, instead of recording votes as transactions on the blockchain. According to the Foundation, a block can then become final after one or two rounds of voting. The existing system, TowerBFT, relies on validator votes building up over 32 slots.

CoinDesk reports that the network is expected to keep using TowerBFT for the first 5,000 slots of epoch 1064, or about 18 minutes, before switching to Alpenglow. That means the epoch’s estimated start time is not the moment the new consensus system takes over.

What will people using Solana notice?

Wallets and apps are expected to keep working as they do now, the Foundation says. The intended change is that users and services waiting for a stronger signal that a transaction cannot be reversed may get it sooner. The upgrade does not change transaction fees or execution, according to the Foundation.

Transaction counts may fall when the upgrade takes effect because validator votes will no longer appear as transactions in blocks. CoinDesk notes that this accounting change could lower reported counts even if trading and payment activity stays at the same pace.

What do validators need to prepare?

Validators need to run software based on Agave 4.3.0 before epoch 1064 begins, according to the Foundation. The Foundation’s page says Firedancer and Frankendancer will not support the initial migration. Validators also need at least 0.8 SOL in their vote account for the admission fee; operators who do not pay it will not vote or produce blocks in the following epoch.

The exact finality speed on mainnet remains unknown until the upgrade is live. The Foundation describes 150 milliseconds as an expectation that can vary with network conditions and the number of voting rounds.

References

• Solana Foundation’s upgrade page — solana.com