nm - nanometer

Collect metrics about observed events with low overhead even in highly multithreaded applications running on 100+ processors.

Using arbitrary development hardware, we measure between 2 and 20 nanoseconds per observation, depending on how the event is configured. Benchmarks are included.

use nm::Event;
use std::time::Duration;

thread_local! {
    static PACKAGES_RECEIVED: Event = Event::builder()
        .name("packages_received")
        .build();
        
    static PACKAGE_SEND_DURATION_MS: Event = Event::builder()
        .name("package_send_duration_ms")
        .build();
}

// observe_once() observes an event with a nominal magnitude of 1
PACKAGES_RECEIVED.with(Event::observe_once);

// observe_millis() observes an event with a magnitude in milliseconds
let send_duration = Duration::from_millis(150);
PACKAGE_SEND_DURATION_MS.with(|e| e.observe_millis(send_duration));

Collected metrics

For each defined event, the following metrics are collected:

• Count of observations (u64).
• Mean magnitude of observations (i64).
• (Optional) Histogram of magnitudes, with configurable bucket boundaries (i64).

More details in the package documentation.

This is part of the Folo project that provides mechanisms for high-performance hardware-aware programming in Rust.