Jaeger

A CNCF-graduated distributed tracing system originally built at Uber. Jaeger ingests trace data from OpenTelemetry-instrumented services, stores it in Elasticsearch or Cassandra, and provides a UI for searching traces, analyzing latency, and finding the root cause of slowdowns in distributed systems.

What is Jaeger?

Jaeger was open-sourced by Uber in 2017 and became a CNCF graduated project in 2019. It solves the problem of diagnosing latency and errors in microservices architectures: when a user request touches 10 services, which one is slow? Jaeger answers that by collecting and correlating distributed traces — a complete record of every service call, database query, and cache hit that occurred during a single request.

Modern Jaeger accepts traces via OTLP (the OpenTelemetry Protocol), making it the natural storage backend when instrumenting with the OpenTelemetry SDK. The legacy Jaeger client libraries are deprecated — all new instrumentation should use OpenTelemetry SDKs pointing at an OTel Collector, which exports to Jaeger.

Architecture

Quick Start (All-in-One Docker)

# All-in-one Jaeger container (dev/testing)
docker run -d --name jaeger   -e COLLECTOR_OTLP_ENABLED=true   -p 6831:6831/udp    # Jaeger Thrift UDP (legacy)
  -p 6832:6832/udp    # Jaeger Thrift Binary UDP (legacy)
  -p 5778:5778         # Agent configs endpoint
  -p 16686:16686       # Jaeger UI
  -p 4317:4317         # OTLP gRPC
  -p 4318:4318         # OTLP HTTP
  -p 14250:14250       # Model.proto gRPC (used by OTel Collector)
  -p 14268:14268       # Jaeger Thrift HTTP (collector)
  jaegertracing/all-in-one:latest

# Open UI at http://localhost:16686

OTel Collector → Jaeger Export

# otel-collector-config.yaml — export to Jaeger
exporters:
  otlp/jaeger:
    endpoint: jaeger:4317
    tls:
      insecure: true

  jaeger:           # legacy gRPC (pre-Jaeger 1.35)
    endpoint: jaeger:14250
    tls:
      insecure: true

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

Kubernetes (Jaeger Operator)

# Install Jaeger Operator via Helm
helm repo add jaegertracing https://jaegertracing.github.io/helm-charts
helm install jaeger-operator jaegertracing/jaeger-operator   --namespace observability --create-namespace

# Minimal Jaeger CR (uses in-memory storage — dev only)
apiVersion: jaegertracing.io/v1
kind: Jaeger
metadata:
  name: jaeger
  namespace: observability
spec:
  strategy: allInOne

# Production Jaeger with Elasticsearch storage
apiVersion: jaegertracing.io/v1
kind: Jaeger
metadata:
  name: jaeger-prod
spec:
  strategy: production
  storage:
    type: elasticsearch
    options:
      es:
        server-urls: https://elasticsearch:9200
  collector:
    replicas: 3
  query:
    replicas: 2