Distributed Tracing in Rails

When a request crosses 4 services, logs in 4 places, traces are the only way to follow it. OpenTelemetry is the vendor-neutral standard — instrument once, export anywhere. This skill sets up production-grade tracing for Rails with minimal noise.

The opinion

Use OpenTelemetry (OTel) — the CNCF standard, vendor-neutral, replaces vendor-specific APM agents. Use auto-instrumentation for Rails, Net::HTTP, Faraday, Sidekiq, Active Record. Propagate context across HTTP (W3C traceparent header), Sidekiq, and Kafka. Sample at the head (parent-based) by default; tune down for high-traffic services. Export to OTLP and let a collector fan out to your backend (Tempo, Honeycomb, Datadog).

Setup

# Gemfile
gem "opentelemetry-sdk"
gem "opentelemetry-exporter-otlp"
gem "opentelemetry-instrumentation-all"