With the recently completed Network Version 27 “Golden Week” upgrade, the whole network is benefiting from F3 improvements that have rolled out since F3 was first activated on Filecoin Mainnet a little over 5 months ago…
Various APIs have been updated or added to consult the F3 sub-system for finality while still falling back to Expected Consensus (EC):
finalized and safe. No client changes are needed. Faster finality is being returned transparently.*ChainGetFinalizedTipSet -* The fully-maintained /v1 ”JSON-RPC” APIs now have ChainGetFinalizedTipSet, which serves as a convenient way to get a finalized tipset to use with other /v1 APIs./v2 APIs - A significant redesign of Filecoin's RPC interface was started for non-Ethereum APIs with important goals of more intuitive interaction patterns, expressiveness with selectors, smaller footprint, future extensibility, and of course, f3 awareness in all relevant APIs. This effort is not complete, but can be used today. Learn more in the V2 API documentation.Here’s a summary of F3-aware APIs:
| API Group | /v1 |
/v2 |
|---|---|---|
| non-Ethereum APIs | ChainGetFinalizedTipSet |
All |
| Ethereum APIs | All | All |
All of these APIs can be used today in one’s local Lotus node or with RPC providers like Glif nodes.
FRC-0108 expands the Filecoin snapshot format to include F3 finality certificates. Previously, nodes needed to get the F3 finality certificate chain from peers outside of the snapshot, which could take hours. Now the F3 state is bundled with the snapshot, both reducing the time and bandwidth required for new nodes to join the network with fast finality. F3-augmented snapshots are produced and hosted by the Forest infra team (download links). As all node implementations (Lotus, Forest, Venus) support this updated format, https://forest-archive.chainsafe.dev/latest/mainnet switched to it by default on October 7.
There were a couple of cases of F3 stalling to make progress after its April activation (1, 2). These events resulted in a whole set of resiliency and performance improvements within go-f3 that the whole network has now adopted. Now that these improvements have been deployed, they’re already showing their impact in the week after the network upgrade. For example, F3 has been staying within 10 epochs from head.