client/authority-discovery: Allow two AuthorityIds to share one PeerId

[mxinden]

Scenario

Say validator V1 is present in the authority set of session S1 with the authority id A1. V1 publishes its network addresses with peer id P1 under the key A1. For session S2 it changes its session keys and thus derives the authority id A1*. It then publishes its network addresses with peer id P1 under the key A1*.

Problem

Another validator V2 would lookup the authorities of both the current and the next session and thus the authority ids A1 and A1*. Today calling get_authority_id_by_peer_id will return either A1 or A1* whereas callers would be interested in both.

substrate/client/authority-discovery/src/service.rs

Line 68 in 179e02b

pub async fn get_authority_id_by_peer_id(&mut self, peer_id: PeerId) -> Option<AuthorityId> {

Solution

Treat the matching between AuthorityId and PeerId as a many to one relationship. One AuthorityId can have at most one PeerId (with deprecation of sentries in mind) at any given point in time. One PeerId can have many AuthorityIds.

[stale]

Hey, is anyone still working on this? Due to the inactivity this issue has been automatically marked as stale. It will be closed if no further activity occurs. Thank you for your contributions.