@shuhei/rolling-window
    TypeScript icon, indicating that this package has built-in type declarations

    1.0.0 • Public • Published

    rolling-window

    Actions Status Codecov npm version

    Implements "Reset reservoir periodically by chunks" strategy to use hdr-histogram-js for monitoring. Inspired by vladimir-bukhtoyarov/rolling-metrics. No additional dependencies.

    See rolling-metrics' documentation for the background.

    Install

    With hdr-histogram-js@2:

    npm install -S hdr-histogram-js @shuhei/rolling-window

    With hdr-histogram-js@1:

    npm install -S hdr-histogram-js@1 @shuhei/rolling-window@^0.2.1

    Usage

    const { RollingWindowHistogram } = require("@shuhei/rolling-window");
     
    // This configuration creates 7 internal histograms (6 + 1) and rotates them
    // one by one in each 10 seconds. `getSnapshot()` returns a histogram of the
    // last 60 to 70 seconds. These additional 0 to 10 seconds make sure that the
    // rolling window can provide a fresh histogram without losing any records at
    // any given time.
    const rollingWindowHistogram = new RollingWindowHistogram({
      timeWindow: 1000 * 60,
      numChunks: 6,
    });
     
    // Record a value
    rollingWindowHistogram.recordValue(value);
     
    // Get a snapshot
    const snapshot = rollingWindowHistogram.getSnapshot();
    const p99 = snapshot.getValueAtPercentile(99);

    API

    new RollingWindowHistogram([options])

    • options
      • timeWindow: number The length of a time window in milliseconds. Default: 60000
      • numChunks: number The number of chunks in the time window. Default: 6
      • buildHistogram: () => Histogram A factory function to create a histogram. This will be called multiple times to prepare necessary histograms in the rolling window. Use this to provide custom options to histograms. Default: build from hdr-histogram-js

    Creates a rolling window histogram with numChunks + 1 histograms in it and starts rotating chunks with an interval of timeWindow / numChunks.

    rollingWindowHistogram.stop()

    Stop the rotation timer. When you stop using a rolling window histogram, make sure to call this method to avoid memory leak.

    rollingWindowHistogram.recordValue(value)

    • value: number A numerical value to record. It must not be negative.

    rollingWindowHistogram.getSnapshot([snapshot])

    • snapshot: Histogram A histogram to accumulate histograms. It is reset before accumulating histograms. If this is not provided, a Histogram is created and kept for reuse.
    • Returns: Histogram

    Keywords

    none

    Install

    npm i @shuhei/rolling-window

    DownloadsWeekly Downloads

    1,833

    Version

    1.0.0

    License

    MIT

    Unpacked Size

    21 kB

    Total Files

    20

    Last publish

    Collaborators

    • shuhei