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Quantile Threshold (Qt)

YAML type: qt | Category: Quantile

Flags daily points vs a historical quantile of the series.

Description

Qt compares each daily point to a global historical percentile boundary (for example P95). No aggregate mode.

How it works

Quantile Threshold (Qt) illustration

Quantile Threshold builds a historical daily percentile (for example P95) from the series, then compares each new daily point to that boundary.

mode may be above or below (quantile detectors do not implement both). There is no period aggregation -- evaluation stays on the daily grain.

Setup

Pick percentile and mode. Higher percentiles mean rarer high-side alerts.

Configure detectors on the data view Analysis tab or in YAML. Validate with Data Preview before enabling production schedules.

Settings

Parameter Default Description
percentile 95 Historical quantile (0-100)
mode above Direction -- see Allowed values

Allowed values

mode

Value Meaning
above Flag values above the quantile boundary
below Flag values below the quantile boundary

both is not implemented for quantile detectors (qt, qtw, qtm).

Shared series filters

Most detectors also accept optional series filters in params:

Parameter Purpose
maxGapAmount Skip series when gap amount is too high (null = no limit). Catalog create-default is often 5.
minValue Skip series whose average value is below this (null = no limit). Catalog create-default is often 1000.
maxValue Skip series whose average value is above this (optional; omit/null = no limit)
useSpecialDates When true, suppress anomalies that overlap special dates

When a filter skips a series, Data Preview shows the reason.

Configuration example

analysis:
  detectors:
    - type: qt
      params:
        percentile: 95
        mode: above

Using the detector

Good baseline when you want distribution-aware thresholds without explicit seasonal models.

Use cases

  • Extreme daily values vs own history
  • Capacity headroom alerts
  • Low-tail detection for under-delivery

Specifics

Weekly/monthly: qtw, qtm.