pyserq.Pool

One pool's report row. Obtain it from Report.pool, Report.pools_named or Report.pools. An array has a row per member. Pool() is not a public constructor; attributes are read-only.

Attributes

Attribute	Type	Description
name	str	Pool declaration name.
index	int or None	Array member index; None for a scalar pool.
mean_used	float	Time-average allocated units after warm-up.
mean_cached	float	Time-average cached units after warm-up.
mean_queue	float	Time-average number of waiting sessions after warm-up.
mean_holders	float	Time-average number of holders after warm-up.
mean_wait	float	Mean queue wait of admissions counted after warm-up.
admissions	int	Admissions over the whole run, including warm-up.
evicted_entries	int	Cache entries fully removed by eviction.
evicted_units	float	Units evicted, including partial eviction.
preemptions	int	Preemptions counted by this pool.
spills	int	Spills of evicted prefixes to another pool.
rejected	int	Requests rejected because static demand could never fit.
stuck	int	Repeated preemptions without progress past the previous preemption.
over_cap	tuple[str, float] or None	At run end, the waiting queue name and demand exceeding this pool's capacity; None when absent.
growing_at_end	int	Holds waiting to grow in this pool when the run ends.
growing_stalled	bool	Every session with an allocation in this pool waits to grow in it: none will free room.

Pool counters include warm-up; time averages and admission wait samples use the measured interval.

See pool statistics for the report's counter and diagnostic conventions.

Examples

import pyserq

source = """
fn main() {
  pool reqs { cap 2; }
  stage svc : fifo;
  workload {
    arrive batch(4);
  }
  server {
    set t0 = now;
    hold reqs (cost(reqs, 1)) { run svc (cost(svc, 2)); }
    observe response = now - t0;
  }
  gauge occupied = used(reqs);
}
"""
report = pyserq.run(pyserq.compile(source=source, horizon=10))
pool = report.pool("reqs")
assert pool is not None
assert pool.index is None
assert pool.admissions == 4
assert pool.over_cap is None

See also

Report, Stage, pool declarations.