AddressBook with multiaddr confidence

[vasco-santos]

As part of the PeerStore improvements epic, we intend to add multiaddr confidence into the AddressBook.

Background

When js-libp2p dials a peer, it tries to dial several known addresses of a peer in parallel. We use a token based dialer to not use a lot of resources to a single connection. However, we don't have a good way of deciding which subset of addresses we should try first. If we gather metrics from peer addresses stored in the PeerStore, we can create a scoring function for the addresses.

Goals

• Know when multiaddrs are successful and when they fail so we can keep track of their confidence (take aborted dials into account)
• Understand the confidence in each multiaddr of a peer so we can manage addresses we store/use/exchange

WIP Notes

• If we dial multiple addrs, and we abort the slower addrs, take into account the confidence of the fastest address
  • Update on success, update on failure, aborts are no ops
  • When the Abort is a timeout abort, treat as a failure for all addresses that were tried
    • Need to account for low dial timeouts poisoning potentially valid address confidence
      • Potentialy weight low dial timeout confidence adjustments
• Parameters: latency, availability, last connection timestamp
• Score function

Relevant Issues

• libp2p/specs#164