Epochs allow nodes to join and leave the network over time. This document provides terminology to describe the different states a node can be in within this lifecycle, and discusses the implications on the flow-go networking layer.

Terminology

Registered Node

• has submitted a registration to the FlowIDTableStaking contract.
• may or may not be selected to join the network in a subsequent epoch.
• ⚠️ Only appears in the FlowIDTableStaking contract, never in the Protocol State

Joining Node

• was previously Registered and was selected to participate in the next epoch. A Registered node becomes AuthorizedJoining when the EpochSetup event is processed.
• it has limited ability to participate in the protocol, only as necessary to prepare for participation in the next epoch, for example:
  • SNs may participate in DKG
  • LNs may participate in Cluster QC voting
  • all nodes may participate in the Block Synchronization protocol, to maintain an up-to-date Protocol State
• has 0 weight

ActiveParticipant Node

• was previously AuthorizedJoining in the previous epoch. A AuthorizedJoining node becomes AuthorizedParticipant at an epoch switchover.
• it has unhindered ability to participate in the protocol as required for its role
• has non-zero weight

AuthorizedLeaving Node

• was previously AuthorizedParticipant and submitted a valid un-registration request in the previous epoch. An AuthorizedParticipant node becomes AuthorizedLeaving at an epoch switchover.
• it was limited ability to participate in the protocol, only as necessary to gracefully terminate its responsibilities, for example:
  • LNs may participate cluster consensus until all transactions valid for inclusion have expired
  • A node may submit or respond to a slashing challenge
• has 0 weight

Ejected Node