Alpenglow
Alpenglow is Solana's upcoming consensus protocol. It replaces Tower BFT's voting and finality logic with Votor and is expected to activate as part of the Agave v4.3 release cycle.
For the protocol design, see:
- The Alpenglow white paper for the complete protocol design.
- SIMD-0326: Alpenglow for the Votor consensus changes.
Operator Changes
For details about changes introduced with Alpenglow, see:
- Validator admission ticket for expected charges, vote account funding requirements, and commission collector configuration.
- Validator failover for vote history file handling and failover steps.
- Commitment status for how the Confirmed and Finalized commitment statuses change.
Block Footers and Geyser Plugins
Alpenglow blocks end with a versioned footer containing various metadata.
For the block footer design, see:
For ease of parsing Agave v4.3 adds an opt-in Geyser notification
for Alpenglow block footers. Plugins that need footer data should return true
from block_footer_notifications_enabled() and implement
notify_block_footer(). Footer callbacks preserve their ordering relative to entry
notifications, but plugins do not need to enable entry notifications to receive
them.
Clock Sysvar
After Alpenglow activates, the Clock sysvar retains its existing layout and
whole-second resolution, but the unix_timestamp field has slightly different
semantics for on-chain programs. During transaction execution, it estimates when
the parent block ended rather than when the current block began.
The slot field still identifies the current slot. Continue treating
the timestamp as approximate and avoid relying on it for high precision.