Logging and Tracing

For most cases, console.log() is a good default choice for JavaScript, since it works with a variety of built-in and third-party logging providers. In JavaScript, a minimal example for structured logging could look like:

let day = "Thursday";
console.log("Hello ", day); // Hello Thursday.

In Rust, a lightweight logging facade is provided by log. It has less features than ILogger, e.g. as it does not yet offer (stable) structured logging or logging scopes. For something with more feature parity to .NET, Tokio offers tracing. tracing is a framework for instrumenting Rust applications to collect structured, event-based diagnostic information. tracing_subscriber can be used to implement and compose tracing subscribers. The same structured logging example from above with tracing and tracing_subscriber looks like:

fn main() {
    // install global default ("console") collector.
    tracing_subscriber::fmt().init();
    tracing::info!("Hello {Day}.", Day = "Thursday"); // Hello Thursday.
}

OpenTelemetry offers a collection of tools, APIs, and SDKs used to instrument, generate, collect, and export telemetry data based on the OpenTelemetry specification. At the time of writing, the OpenTelemetry Logging API is not yet stable and the Rust implementation does not yet support logging, but the tracing API is supported.