Crate tokio_metrics_collector

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Expand description

Provides utilities for collecting Prometheus-compatible metrics from Tokio runtime and tasks. You can find metrics definition here.

Collecting task metrics

In the below example, a TaskCollector is constructed and used to instrument a simple task. Task metrics is collected every second.

use prometheus::Encoder;

#[tokio::main]
async fn main() {
    // register global task collector
    let task_collector = tokio_metrics_collector::default_task_collector();
    prometheus::default_registry()
        .register(Box::new(task_collector))
        .unwrap();

    // construct a TaskMonitor
    let monitor = tokio_metrics_collector::TaskMonitor::new();
    // add this monitor to task collector with label 'simple_task'
    // please use unique labels for each monitor and
    // instrument multiple tasks by the `instrument` function.
    task_collector.add("simple_task", monitor.clone());

    // spawn a background task and instrument
    tokio::spawn(monitor.instrument(async {
        loop {
            // do something here
            tokio::time::sleep(tokio::time::Duration::from_millis(500)).await;
        }
    }));

    // print metrics every tick
    for _ in 0..5 {
        tokio::time::sleep(tokio::time::Duration::from_secs(1)).await;

        let encoder = prometheus::TextEncoder::new();
        let mut buffer = Vec::new();
        encoder
            .encode(&prometheus::default_registry().gather(), &mut buffer)
            .unwrap();
        let data = String::from_utf8(buffer.clone()).unwrap();

        println!("{}", data);
    }
}

Collecting runtime metrics

This functionality requires tokio_unstable and the crate feature rt.

In the below example, a RuntimeCollector is constructed and used to collect tokio runtime metrics every second.

use prometheus::Encoder;

#[tokio::main]
async fn main() {
    // register global runtime collector
    prometheus::default_registry()
        .register(Box::new(
            tokio_metrics_collector::default_runtime_collector(),
        ))
        .unwrap();

    // print metrics every tick
    for _ in 0..5 {
        tokio::time::sleep(tokio::time::Duration::from_secs(1)).await;

        let encoder = prometheus::TextEncoder::new();
        let mut buffer = Vec::new();
        encoder
            .encode(&prometheus::default_registry().gather(), &mut buffer)
            .unwrap();
        let data = String::from_utf8(buffer.clone()).unwrap();

        println!("{}", data);
    }
}

Structs

Functions