Crate nm_otel 

nm_otel - OpenTelemetry bridge for nm metrics

This crate provides a bridge between nm metrics and OpenTelemetry, enabling export of nm-collected metrics to any OpenTelemetry-compatible backend.

Quick start

use std::time::Duration;
use nm_otel::Publisher;
use tick::Clock;

// In your async runtime, periodically export all nm metrics to OpenTelemetry.
Publisher::builder()
    .provider(my_meter_provider)
    .clock(Clock::new_tokio())
    .interval(Duration::from_secs(60))
    .build()
    .publish_forever()
    .await;

Exported metrics

Each nm::Event is exported as one or more OpenTelemetry metrics:

nm data	OpenTelemetry type	Metric name
count	counter	{event}
sum	gauge	{event}_sum
histogram	counter per bucket	{event}_bucket with le attribute

Histogram format

Histograms are exported as separate counter and gauge metrics because the OpenTelemetry Rust SDK does not yet support recording pre-aggregated histogram data. See opentelemetry-rust#2505.

The format uses cumulative bucket counts with a le (less-than-or-equal) attribute:

http_latency_ms_bucket{le="10"}   → observations ≤ 10
http_latency_ms_bucket{le="50"}   → observations ≤ 50
http_latency_ms_bucket{le="100"}  → observations ≤ 100
http_latency_ms_bucket{le="+Inf"} → all observations
http_latency_ms                   → total observation count
http_latency_ms_sum               → sum of all observed values

Configuration

Use PublisherBuilder to configure the publisher:

• interval() - how often to collect and export metrics (default: 5 seconds)
• meter_name() - OpenTelemetry meter name (default: “nm”)
• provider() - custom SdkMeterProvider

Requirements

The publisher runs as an infinite async task that should be spawned in your application’s async runtime. Pass an appropriate tick::Clock to the builder for your runtime (e.g., Clock::new_tokio() for Tokio).

Structs

Publisher

Publishes nm metrics to OpenTelemetry.

PublisherBuilder

Builder for configuring an nm-to-OpenTelemetry publisher.