1 unstable release

0.1.0	Mar 22, 2026

#2 in #kafka

MIT/Apache

18KB
219 lines

prometheus-extensions

Prometheus extensions for richer metric collection in Rust.

Types

Type	Purpose
`AggregateCounter`	A `CounterVec` wrapper that automatically emits an extra unlabeled total alongside every per-label counter.
`ScientificEncoder`	A Prometheus text-format encoder that renders values in scientific notation with a trailing comma after the last label (Kafka JMX exporter compatible).
`Sensor`	A lock-free exponential moving average (EMA) gauge for tracking smoothed rates.

Usage

use prometheus::Opts;
use prometheus::core::Collector;
use prometheus_extensions::{AggregateCounter, ScientificEncoder};

let counter = AggregateCounter::new(
    Opts::new("http_requests_total", "Total HTTP requests"),
    &["method"],
).unwrap();

counter.with_label_values(&["GET"]).inc_by(100.0);
counter.with_label_values(&["POST"]).inc_by(42.0);

// Collecting yields 3 metrics: unlabeled total (142) + two labeled.
let families = counter.collect();

// Encode in scientific notation
let encoder = ScientificEncoder::new();
let mut buf = Vec::new();
encoder.encode(&families, &mut buf).unwrap();

License

Licensed under either of Apache License, Version 2.0 or MIT license at your option.

Dependencies

~0.5–1.2MB
~25K SLoC