jaegertracing/jaeger

What Jaeger does

Jaeger is a distributed tracing platform for observing requests as they move across services. Applications instrumented with an OpenTelemetry SDK send trace data over HTTP or gRPC to the Jaeger Collector, which writes to a storage backend; the Query service reads that data for the Jaeger UI, and the collector can also return sampling decisions to SDKs README architecture diagram.

It originated at Uber and is a CNCF graduated project, with separate repositories for the UI and data model. Backend integrations include Elasticsearch, OpenSearch, Cassandra, and ClickHouse, each with its own Docker Compose setup for testing backend support policy.

It is aimed at teams operating microservices or Kubernetes workloads that need to inspect request flows, latency, and service dependencies rather than only aggregate metrics or logs.

Quick start

Docker is the only prerequisite for the all-in-one setup, which bundles the UI, collector, query service, and in-memory storage:

docker run --rm --name jaeger \
  -p 16686:16686 \
  -p 4317:4317 \
  -p 4318:4318 \
  jaegertracing/jaeger:latest

Open the Jaeger UI at http://localhost:16686, then point an OpenTelemetry-instrumented application at OTLP gRPC port 4317 or OTLP HTTP port 4318. Traces appear in the UI for searching and dependency analysis.

This all-in-one mode uses in-memory storage and is intended for evaluation. Production deployments need a persistent backend and should follow the getting started guide.

Constraints and operational notes

• Storage choice is an operational decision: version coverage follows each backend's upstream lifecycle, and versions outside that policy get at best-effort support only.
• Jaeger v2 builds on OpenTelemetry Collector components. Deprecated configuration options are kept for at least three months or two minor releases, whichever is later, so upgrades can require configuration changes version compatibility guarantees.
• Building from source tracks supported Go releases; when a new Go minor version lands, the previous one is dropped as a supported build version.
• The repository is Apache-2.0 licensed and the project is governed through CNCF and its maintainer documents.

HotRepo's take

Jaeger's long-running place in the observability stack matches its stable GitHub footprint: 23,408 stars and 3,246 forks, with a recent daily Go-language snapshot showing one new star and a best Go ranking of 13th on 2026-11-15. The 2017 Hacker News thread drew 311 points and 63 comments, where users compared Jaeger with Zipkin and one reported getting a working visualization in about two hours HN discussion user experience. That attention dates from the project's CNCF incubation period, so it reflects historical interest rather than current adoption.