Gossipsub 1.1 | PeerScoring and Score Function

[lla-dane]

The remaining steps for Gossipsub 1.1 upgrade as follows -

• Direct Peers
• Peer Exchange & Prune Backoff
• Score Function
• Peer Scoring

Progress so far:

• The Direct Peers PR has been merged.
• Peer Exchange & Prune Backoff have been implemented.

What remains:

1. Signed-peer-records in PeerExchange:

   • Extent the PRUNE control message to carry an optional set of peers, each with PeerID and a signed peer record.
   • If a signed peer record is omitted, the receiving peer must rely on ambient peer discovery to resolve addresses.
   • Implement the handler for validating signed peer records during PX, including signature checks and sequence/timestamp freshness.
   • Update the peerstore with validated records (when available)

2. Score Function:

   • Implement the score function as specified in the Gossipsub 1.1 spec
   • This includes topic-scoped scores (P1 - P4) and global scores (P5 - P7).
   • Each parameter must support weights, caps, and decay to model the expected peer behavior.

3. Peer Scoring:

   • Integration of the score function with the Gossipsub protocol logic.
   • Score gates for gossip, publish, PX acceptance, graylisting.
   • Incorporate opportunistic grafting based on median scores.
   • Ensure scoring updates are triggered on message delivery, validation, mesh participation, and control message handling.

Gossipsub 1.1 spec: https://github.com/libp2p/specs/blob/master/pubsub/gossipsub/gossipsub-v1.1.md

[seetadev]

@lla-dane : Great, thank you for doing a careful study and sharing the insights on Gossipsub.

This is not only useful to Gossipsub 1.1 but 1.2 as well. CCing @Winter-Soren.