Module control 

Control plane: leader election, assignment snapshots, barrier coordination. Cluster control plane: leader election, assignment snapshots, and barrier coordination.

Re-exports

pub use barrier::BarrierAck;

pub use barrier::BarrierAnnouncement;

pub use barrier::BarrierCoordinator;

pub use barrier::ClusterKv;

pub use barrier::InMemoryKv;

pub use barrier::Phase;

pub use barrier::QuorumOutcome;

pub use barrier::ACK_KEY;

pub use barrier::ANNOUNCEMENT_KEY;

pub use controller::ClusterController;

pub use crate::checkpoint_decision::CheckpointDecisionStore;

pub use crate::checkpoint_decision::DecisionError;

pub use catalog_manifest::CatalogManifest;

pub use catalog_manifest::CatalogManifestEntry;

pub use catalog_manifest::CatalogManifestError;

pub use catalog_manifest::CatalogManifestStore;

pub use leader::leader_of;

pub use leader_lease::lease_grants_leadership;

pub use leader_lease::LeaderLease;

pub use leader_lease::LeaderLeaseConfig;

pub use leader_lease::LeaderLeaseManager;

pub use leader_lease::LeaderLeaseStore;

pub use leader_lease::LeaseError;

pub use leader_lease::LeaseOutcome;

pub use snapshot::AssignmentSnapshot;

pub use snapshot::AssignmentSnapshotStore;

pub use snapshot::RotateOutcome;

pub use snapshot::SnapshotError;

pub use chitchat_kv::ChitchatKv;

pub use query::remote_scan_client;

pub use query::QueryClientPool;

pub use query::QueryHandlerSlot;

pub use query::RemoteBatchStream;

pub use query::RemoteQueryHandler;

pub use tls::set_cluster_tls;

pub use tls::ClusterTls;

Modules

barrier

Cross-instance barrier protocol. Direct gRPC leader-to-follower calls under cluster, falling back to gossip-KV announce/ack/poll.

catalog_manifest

Cluster-wide catalog manifest: the ordered DDL needed to rebuild a node’s logical catalog (sources, tables, streams, materialized views, sinks).

chitchat_kv

Chitchat-backed ClusterKv. Reads filter by live_nodes() so suspected peers don’t count toward quorum.

controller

Facade over ClusterKv + BarrierCoordinator + membership watch. None on CheckpointCoordinator means single-instance mode.

leader

Weak leader election: lowest-ID live instance wins. Split-brain is tolerated because epoch=N/_COMMIT is CAS-guarded.

leader_lease

CAS-backed leader lease with TTL and a monotonic fencing token. One object per sequence at control/leader-lease/v{seq:016}.json, written with PutMode::Create so the CAS works on every backend (LocalFileSystem included). The lease prevents split-brain: a stale leader whose lease has expired loses the CAS to whoever acquires next, and the fencing token advances only on an owner change so followers can reject writes carrying a stale token.

query

In-engine distributed query (pull path): a coordinator fans RemoteScan out to peers owning part of a table/MV and unions their Arrow batches.

snapshot

Durable vnode→instance assignment snapshots. One object per version at control/assignment-snapshots/v{N:016}.json. Chitchat carries the ephemeral copy; these files survive full-cluster restart.

tls

Process-wide mutual TLS for the cluster control plane (barrier, query, shuffle). One identity per node/process, installed once at startup.