Crate atomr_cluster 

atomr-cluster.

Contains membership, gossip, reachability, heartbeat, and the split-brain resolver strategies.

Structs

ClusterDaemonHandle

Public handle to a running ClusterDaemon.

ClusterEventBus

In-process cluster events bus.

ClusterRemoteAdapter

CrossDcSettings

Slow-path settings used for cross-DC heartbeats / gossip.

DaemonConfig

Configuration knobs.

DaemonSnapshot

Snapshot of the daemon state used by peer_state queries.

DownAllStrategy

DownAll: unconditionally downs every member on both sides of the partition. Used when the operator prefers cluster-wide restart over any chance of split-brain (matches “down-all-when-unstable” in related industry SBR catalogs).

Gossip

GossipOverview

Snapshot of seen-by + unreachable info.

HeartbeatSender

In-memory heartbeat-sender state.

HeartbeatState

InProcessClusterTransport

Channel-backed cluster transport. Discovers peers through a shared InProcessRegistry. Construct one per node, register the daemon’s gossip inbox + a RemoteMessageSink via Self::start, and call Self::send_remote to push remote-tells.

InProcessRegistry

Shared registry that wires up InProcessClusterTransport siblings in the same process. A single registry is created once per “logical network” and handed to every transport that should be able to reach every other.

KeepMajorityStrategy

KeepMajority: the side with strictly more up members survives.

KeepOldestStrategy

KeepOldest: the side containing the oldest (lowest up_number) up member survives.

KeepReferee

KeepReferee: the side containing the designated referee member survives.

LeaderHandover

Watcher that detects leader transitions across successive MembershipState snapshots. Stateful: holds the previous snapshot’s leader and emits a LeaderHandoverEvent only on change.

LeaderHandoverEvent

Handover event emitted by a LeaderHandover watcher when the elected leader changes between snapshots. Cluster.LeaderChanged event published on the cluster’s domain event stream.

LeaseMajorityStrategy

LeaseMajority: majority decision gated by an external lease. In-memory simulation of whether a lease was acquired.

Member

MembershipState

NoSbr

Marker DowningStrategy used when no SBR runtime is installed.

PeerHeartbeat

Per-peer heartbeat record kept by the sender.

Reachability

RecordingSink

Test-only sink that buffers every received RemoteTell for later inspection. Public so binding-side tests can use it.

RemoteTellRecord

SbrRuntime

Runtime that pairs a strategy with a stability deadline.

SplitBrainResolver

Facade that holds any of the strategies behind a trait object.

StaticQuorumStrategy

StaticQuorum: requires at least quorum_size reachable members to survive.

SubscriptionHandle

RAII handle returned by ClusterEventBus::subscribe. Dropping it removes the corresponding subscriber.

TcpClusterTransport

TCP-based cluster transport. One listener per node accepts inbound connections; outbound connections are opened on demand and reused per peer address. Frames are length-prefixed (4-byte big-endian) bincode-encoded ClusterFrames.

VectorClock

Enums

ClusterEvent

Event variants published on ClusterEventBus.

ClusterFrame

Wire-level frame used by both InProcessClusterTransport and TcpClusterTransport. The two variants are multiplexed over the same connection so that gossip and Python-level remote-tells share the same association.

DaemonCmd

Control commands accepted by the daemon mailbox.

DowningDecision

What the resolver recommends the cluster do with the given side.

GossipDecision

Decision the receiver makes after comparing version vectors.

GossipPdu

One gossip exchange. Sender hands a GossipStatus to the peer; peer responds with either a full GossipEnvelope (if it has newer state) or a GossipMerge request (if its state is older).

MemberStatus

ReachabilityStatus

SbrAction

Action emitted by SbrRuntime::tick.

VectorRelation

Constants

DC_ROLE_PREFIX

Convention: a member’s data-center is encoded as a role of the form "dc-<name>". uses the same prefix.

DEFAULT_DC

Default DC name used when no dc-* role is present.

Traits

DowningStrategy

GossipTransport

Pluggable transport for gossip PDUs.

RemoteMessageSink

Sink for inbound RemoteTell frames. The pycore binding implements this — typically by decoding the payload via the codec registry and invoking tell on the matching local actor.

Functions

elect_leader

Pick the deterministic leader from a MembershipState.

gossip_decide

Pure decision function: given the local + remote version vectors, what should we do?

heartbeat_interval_for

Pick the heartbeat interval to use against peer from the perspective of local: in-DC peers get local_interval, cross-DC peers get cross.heartbeat_interval.

is_converged

Convergence holds when every member that this node believes is alive is also reachable. gossip uses convergence as a pre-condition for the leader’s status-transition tick (the leader won’t move members from Joining → Up while a partition is in flight).

member_dc

Extract the data-center name from a member’s role list. Returns DEFAULT_DC when no dc-* role is set.

next_status

Compute the next status for a member given the current convergence state. Returns None if no transition applies.

partition_by_dc

Partition a peer list into (in_dc, cross_dc) from local’s perspective.

pick_gossip_target

Pick the next peer to gossip with, given a list of known peer addresses and a per-tick cursor. Skips self_addr.

same_dc

true if a and b belong to the same data-center.

spawn_daemon

Spawn a daemon. The caller provides a transport implementation; the daemon never blocks on it.

spawn_daemon_with_sbr

Same as spawn_daemon but installs an SBR runtime.