Struct MetricsSnapshot 

pub struct MetricsSnapshot {

    pub lifecycle: Option<DaemonLifecycleSnapshot>,
    pub wal_pages: Option<u64>,
    pub wal_log_frames: Option<u64>,
    pub wal_checkpointed_frames: Option<u64>,
    pub wal_pending_frames: Option<u64>,
    pub wal_physical_bytes: Option<u64>,
    pub wal_observed_at_unix_ms: Option<u64>,
    pub wal_checkpoint_stores: Vec<CheckpointStoreMetrics>,
    pub wal_truncate_attempts: u64,
    pub wal_truncate_consecutive_failures: u64,
    pub wal_checkpoint_skipped_ticks: u64,
    pub wal_checkpoint_consecutive_skips: u64,
    pub wal_checkpoint_last_skip_wal_pages: Option<u64>,
    pub oldest_pinned_tx_micros: Option<u64>,
    pub oldest_pinned_tx_label: Option<String>,
    pub open_tx_count: usize,
    pub write_queue_depth: Option<usize>,
    pub write_queue_capacity: Option<usize>,
    pub write_last_queue_wait_micros: Option<u64>,
    pub write_last_transaction_acquire_micros: Option<u64>,
    pub write_last_body_micros: Option<u64>,
    pub write_last_commit_micros: Option<u64>,
    pub write_last_total_micros: Option<u64>,
    pub write_last_observed_at_unix_ms: Option<u64>,
    pub connections: Option<ConnectionCapSnapshot>,
    pub recall_ledger: Option<RecallLedgerSnapshot>,
}

Point-in-time snapshot of the daemon’s server-side gauges — the load/perf harness read-surface (measurement substrate, not a product feature).

Every field here is a server-side gauge reachable from handle_conn without any mutation: khive_storage::tx_registry (ADR-091 Plank 0, process-global singleton), the main pool’s backend-keyed routine WAL sample and process TRUNCATE counters (khive_db::checkpoint), and the ADR-067 Component A write queue depth/latest writer-stage sample. There is no reset reachable through this type or through DaemonRequestFrame — gauges out, nothing in.

Fields

lifecycle: Option<DaemonLifecycleSnapshot>

Launch mode and the current lifecycle of this daemon incarnation.

wal_pages: Option<u64>

Last-observed WAL page count from the periodic checkpoint tick. None when the checkpoint task has never ticked in this process (for example, an in-memory dispatcher with no pool, or a daemon that just started and hasn’t hit its first tick yet).

wal_log_frames: Option<u64>

Logical frames present in the WAL at the main backend’s most recent periodic PASSIVE checkpoint. Kept separate from physical allocation.

wal_checkpointed_frames: Option<u64>

Frames backfilled by that same periodic PASSIVE pass.

wal_pending_frames: Option<u64>

Logical frames still pending after that pass (log - checkpointed).

wal_physical_bytes: Option<u64>

Physical -wal sidecar bytes captured at the same routine tick.

wal_observed_at_unix_ms: Option<u64>

Wall-clock timestamp of the routine WAL sample, for staleness checks.

wal_checkpoint_stores: Vec<CheckpointStoreMetrics>

Cumulative actual routine PASSIVE calls for each store this daemon checkpoints. Microseconds preserve sub-millisecond costs; max is since process start, not an interval maximum. Counters saturate rather than wrap.

wal_truncate_attempts: u64

Total WAL TRUNCATE escalation attempts (ADR-091 Plank 2) made in this process’s lifetime, regardless of whether they succeeded in reclaiming pages.

wal_truncate_consecutive_failures: u64

Current consecutive-failure count for TRUNCATE attempts that failed to bring the WAL back below warn_pages; resets to 0 the next time an attempt clears it.

wal_checkpoint_skipped_ticks: u64

Total checkpoint ticks skipped because the dedicated checkpoint connection was unavailable (ADR-091 checkpoint-pressure telemetry), across this process’s lifetime. #[serde(default)] so an older client decoding a newer daemon’s snapshot (or vice versa) does not fail.

wal_checkpoint_consecutive_skips: u64

Current consecutive-skip run length; 0 once the next tick is observed.

wal_checkpoint_last_skip_wal_pages: Option<u64>

WAL page count last known at the time of the most recent skip, if any skip has occurred yet in this process.

oldest_pinned_tx_micros: Option<u64>

Age, in microseconds, of the oldest currently-open transaction registry entry (ADR-091 Plank 0). None when no transaction is currently open.

oldest_pinned_tx_label: Option<String>

Diagnostic label of the oldest currently-open transaction registry entry, if any and if it was registered with one.

open_tx_count: usize

Number of currently open transaction registry entries.

write_queue_depth: Option<usize>

Current write-queue backlog depth (ADR-067 Component A): requests enqueued but not yet accepted by the WriterTask drain loop. None unless the write queue is enabled (KHIVE_WRITE_QUEUE=1) and a file-backed pool is available.

write_queue_capacity: Option<usize>

The write queue’s configured bounded capacity (PoolConfig::write_queue_capacity), gated the same as write_queue_depth.

write_last_queue_wait_micros: Option<u64>

Latest completed writer-task span: bounded-channel admission/backlog.

write_last_transaction_acquire_micros: Option<u64>

Latest completed writer-task span: BEGIN IMMEDIATE acquisition.

write_last_body_micros: Option<u64>

Latest completed writer-task span: application transaction body.

write_last_commit_micros: Option<u64>

Latest completed writer-task span: SQLite COMMIT/fsync phase.

write_last_total_micros: Option<u64>

Whole latest writer-task request span, retained for compatibility and comparison with the decomposed stages.

write_last_observed_at_unix_ms: Option<u64>

Wall-clock timestamp of the writer-stage sample.

connections: Option<ConnectionCapSnapshot>

Connection cap of the daemon socket this snapshot was served from. None from a daemon that predates the cap and when no listener owns the connection.

recall_ledger: Option<RecallLedgerSnapshot>

Bounds and counts of the best-effort recall serve-ledger tasks. None from a daemon that predates the bound.

Trait Implementations

impl Clone for MetricsSnapshot

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for MetricsSnapshot

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for MetricsSnapshot

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for MetricsSnapshot

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for MetricsSnapshot

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl Serialize for MetricsSnapshot

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for MetricsSnapshot