log-io vs std-logger vs graflog

Structured logging pipeline for Rust. Zero-allocation fast path, JSON / logfmt / human-readable outputs, context propagation (request-id, trace-id), per-module filtering, async-safe sinks. An IO pipeline for log records, not a wrapper around log+tracing.

A logging implementation for the log crate that logs messages to standard error and requests to standard out. It support a number of output formats including JSON, JSON for GCP (gcloud) and logfmt.

Structured JSON logging for Rust applications optimized for Grafana ingestion