Struct ReaderAcquisitionSnapshot 

pub struct ReaderAcquisitionSnapshot {

    pub reader_admission_capacity: usize,
    pub available_reader_admission_slots: usize,
    pub acquisitions: u64,
    pub pooled_checkouts: u64,
    pub standalone_opens: u64,
    pub infrastructure_standalone_opens: u64,
    pub checkout_timeouts: u64,
    pub active_pooled_checkouts: u64,
    pub peak_active_pooled_checkouts: u64,
    pub completed_pooled_checkouts: u64,
    pub max_completed_hold_micros: u64,
    pub max_completed_hold_operation: Option<&'static str>,
    pub reader_replacement_open_failures: u64,
}

Process-local reader acquisition and hold lifecycle since one ConnectionPool was constructed.

Counters are monotonic and reset only when the pool is reconstructed. active_pooled_checkouts is the point-in-time number of live ReaderGuard values. Hold duration includes connection reset or replacement on return, because the slot is not reusable before then.

Fields

reader_admission_capacity: usize

Configured process-local admission budget shared by pooled readers and the explicit raw-SQL read-transaction exception.

available_reader_admission_slots: usize

Point-in-time permits not held by either pooled readers or explicit raw-SQL read transactions.

acquisitions: u64

Successful request-path reader acquisitions (pooled plus the explicit raw-SQL transaction exception; infrastructure opens excluded).

pooled_checkouts: u64

Successful bounded pooled-reader checkouts.

standalone_opens: u64

Successful request-path standalone opens from the closed exception list (currently explicit raw-SQL deferred transactions only).

infrastructure_standalone_opens: u64

Successful boot/diagnostic standalone opens, attributed separately so request traffic cannot be inferred from infrastructure activity.

checkout_timeouts: u64

Reader-admission waits that exhausted checkout_timeout before any query began. Covers pooled checkout and the closed raw-SQL exception; cooperative request cancellation is intentionally excluded.

active_pooled_checkouts: u64

Pooled checkouts live at the instant this snapshot was taken.

peak_active_pooled_checkouts: u64

High-water mark of concurrent pooled checkouts.

completed_pooled_checkouts: u64

Pooled guards that completed their full return/reset lifecycle.

max_completed_hold_micros: u64

Longest completed checkout hold, including return/reset, in microseconds. Diagnostic evidence only; never a test timing gate.

max_completed_hold_operation: Option<&'static str>

The typed-store operation that held the checkout reported in max_completed_hold_micros. None when that hold came from a route that carries no operation name, which is itself the answer rather than a missing reading (#2793).

reader_replacement_open_failures: u64

A disqualified pooled-reader return (reset/pristine-check failure) whose replacement connection then also failed to open, permanently shrinking the physical pool by one slot below max_readers. Logged at warn when it happens; this counter makes the shrink observable in a snapshot too, since the pool itself never re-grows on its own.

Trait Implementations

impl Clone for ReaderAcquisitionSnapshot

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for ReaderAcquisitionSnapshot

impl Debug for ReaderAcquisitionSnapshot

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

Formats the value using the given formatter.

impl Default for ReaderAcquisitionSnapshot

fn default() -> Self

Returns the “default value” for a type.

impl Eq for ReaderAcquisitionSnapshot

impl PartialEq for ReaderAcquisitionSnapshot

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for ReaderAcquisitionSnapshot