OpenTelemetry Instrumentation

OpenTelemetry Overview

OpenTelemetry (OTel) is a vendor-neutral standard for collecting telemetry data. It provides SDKs for metrics, logs, and traces in multiple languages. OTel replaces vendor-specific instrumentation with a single, portable API.

SDK Setup

The OTel SDK configures the API with exporters, processors, and resource information. Each language has its own SDK package. The setup pattern is consistent: create a resource, configure exporters, and initialize the SDK.

Resource Attributes

Resource attributes describe the entity producing telemetry. They include service name, version, environment, and deployment details. These attributes are attached to every span, metric, and log from the service.

Auto-Instrumentation

Auto-instrumentation adds tracing and metrics to your application without code changes. Language-specific agents hook into libraries and frameworks automatically. This gives you immediate visibility with minimal effort.

# Download the Java agent
wget https://github.com/open-telemetry/opentelemetry-java-instrumentation/releases/latest/download/opentelemetry-javaagent.jar

# Run with the agent
java -javaagent:opentelemetry-javaagent.jar \
     -Dotel.service.name=my-service \
     -Dotel.exporter.otlp.endpoint=http://otel-collector:4317 \
     -jar my-service.jar

Context Propagators

Propagators serialize and deserialize trace context across service boundaries. W3C TraceContext is the default and recommended format. It uses the traceparent header to carry trace ID and span ID between services.

# Header format
traceparent: 00-abc123def456789-a1b2c3d4e5f6-01

# Components:
# 00               - version
# abc123def456789  - trace ID
# a1b2c3d4e5f6    - parent span ID
# 01               - trace flags (sampled)

Collector Role

The OTel Collector sits between your application and backends. It receives telemetry, processes it (batching, filtering, enrichment), and exports it to one or more backends. The Collector decouples your application from backend-specific configuration.

receivers:
  otlp:
    protocols:
      grpc:
        endpoint: 0.0.0.0:4317
      http:
        endpoint: 0.0.0.0:4318

processors:
  batch:
    timeout: 5s
    send_batch_size: 1000

exporters:
  otlp:
    endpoint: tempo:4317
    tls:
      insecure: true

service:
  pipelines:
    traces:
      receivers: [otlp]
      processors: [batch]
      exporters: [otlp]