Back to roadmap

intermediate ยท Module 2.1

OpenTelemetry Core Concepts

Learning Objectives

  • Explain the OTel signal model (traces, metrics, logs) and the SDK/API split.
  • Describe context propagation and the role of the W3C traceparent header.
  • Understand why OTel decouples instrumentation from the backend vendor.

Key Concepts

API vs SDK

The OTel API is what your OTT service code calls; the SDK provides the concrete implementation (samplers, processors, exporters). Swapping backends means changing SDK config, not application code.

Context propagation

OTel propagates trace context across service boundaries via the W3C traceparent header so spans from Gateway, Auth, and Playback join one trace.

Vendor-neutral signals

OTLP is the wire protocol; because it is standardized, the same instrumentation can export to Jaeger, Tempo, or a commercial backend without rewrites.

Insight

OTel's biggest win is portability: instrument once, re-point the Collector exporter to migrate backends.

Info

The traceparent header carries the trace-id, parent span-id, and sampling flag in a compact hex format.

Knowledge Check

  1. 1. What is the difference between the OpenTelemetry API and SDK?

  2. 2. Which header carries trace context across OTT service boundaries?

  3. 3. Why is OpenTelemetry described as vendor-neutral?