Struct PeekWalkMetrics 

pub(super) struct PeekWalkMetrics {
    walks_inline: IntCounter,
    walks_offloaded: IntCounter,
    walks_stashed: IntCounter,
    error_scan_seconds: Histogram,
    cursor_setup_seconds: Histogram,
    row_iteration_seconds: Histogram,
    row_iteration_rows: Histogram,
    result_sort_seconds: Histogram,
    result_sort_rows: Histogram,
    row_collection_seconds: Histogram,
    permit_queue_depth: UIntGauge,
    permit_wait_seconds: Histogram,
}

The metrics an index peek walk reports, on either substrate.

Cloned into an offloaded walk’s task, so that a walk reports the same phases wherever it ran.

Fields

walks_inline: IntCounter

Counts walks that ended on the timely worker.

walks_offloaded: IntCounter

Counts walks that ended away from the timely worker.

walks_stashed: IntCounter

Counts walks that answered from the peek response stash.

error_scan_seconds: Histogram

cursor_setup_seconds: Histogram

row_iteration_seconds: Histogram

row_iteration_rows: Histogram

result_sort_seconds: Histogram

result_sort_rows: Histogram

row_collection_seconds: Histogram

permit_queue_depth: UIntGauge

How many offloaded walks are waiting for a permit. Reported by the offloaded driver alone, which is the only one that queues.

permit_wait_seconds: Histogram

How long an offloaded walk waited for its permit. Reported by the offloaded driver alone.

Implementations

impl PeekWalkMetrics

pub(super) fn new(metrics: &WorkerMetrics) -> Self

pub(super) fn queued_for_permit(&self) -> PermitWait

Accounts for an offloaded walk joining the queue for a permit.

The returned guard leaves the queue however the wait ends, a cancellation and an abort included, so the depth cannot drift up over a process’s life.

pub(super) fn walked_inline(&self)

Counts a walk that the timely worker drove to an outcome.

A walk that suspends leaves the worker rather than finishing here, so a peek answered from the peek stash never counts here: the driver that writes to the stash is the offloaded one.

pub(super) fn walked_offloaded(&self)

Counts a walk that an offloaded task drove to an outcome, whatever that outcome is.

A walk cancelled while queued or while running counts on neither substrate, as does one whose task died without an outcome, which the worker answers with an error of its own. The two therefore sum to the walks that reached an outcome rather than to the peeks answered.

pub(super) fn walked_to_stash(&self)

Counts a walk that answered with a handle to the peek response stash.

Counted alongside Self::walked_offloaded rather than instead of it, so the two substrates still sum to the walks that ended.

pub(super) fn observe_error_phase(&self, phases: &WalkPhases)

Reports the phases that precede the walk over the ok trace.

Reported for every terminal outcome, a hand-off to the peek stash included, because both phases are over by then whatever the walk does next.

pub(super) fn observe_ok_phase(&self, phases: &WalkPhases)

Reports the walk over the ok trace, for a walk that completed it. A walk that ends any other way reports nothing here: the rows it examined are not the rows an answer took.

pub(super) fn observe_row_collection(&self, elapsed: Duration)

Reports the time rows_response took.

Trait Implementations

impl Clone for PeekWalkMetrics

fn clone(&self) -> PeekWalkMetrics

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PeekWalkMetrics

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

Formats the value using the given formatter.