Struct Sender 

pub struct Sender {

    pub listener: ReplicationListener,
    pub repl_consumer_1: ReplicationConsumer,
    pub repl_consumer_2: ReplicationConsumer,
    pub replica_slots: Arc<ReplicaSlotCursors>,
    pub store: NodeStore,
    pub authorized_keys: Arc<AuthorizedKeys>,
    pub evict_flags: [Arc<AtomicBool>; 2],
    pub active_flags: [Arc<AtomicBool>; 2],
    pub metrics: Arc<ReplicationMetrics>,
    pub handlers: [Placement; 2],
    pub batch_size: usize,
    pub heartbeat_secs: u64,
    pub fence_state: Arc<FenceState>,
}

Fields

listener: ReplicationListener

Pre-bound replication listener, non-blocking by construction. Bound by the caller at startup — not here — so a bad or stolen --replication-bind port fails the boot with a clear error. Binding on this thread meant a failure only killed the sender silently, leaving a primary that looked healthy but could never satisfy disk+ram/two-disks acks.

repl_consumer_1: ReplicationConsumer

repl_consumer_2: ReplicationConsumer

replica_slots: Arc<ReplicaSlotCursors>

store: NodeStore

The node’s journal, streamed to replicas, and its snapshot, sent to one that needs a resync.

authorized_keys: Arc<AuthorizedKeys>

evict_flags: [Arc<AtomicBool>; 2]

active_flags: [Arc<AtomicBool>; 2]

metrics: Arc<ReplicationMetrics>

handlers: [Placement; 2]

Where each replica handler thread runs and how it waits on its replication ring, by slot.

batch_size: usize

heartbeat_secs: u64

fence_state: Arc<FenceState>

Node fencing state. Read to stamp the primary’s epoch onto each StreamStart, and to self-demote when a replica handshakes with a higher epoch (this primary has been superseded). See crate::fence.