Jaeger is an open source distributed tracing platform. It shows how requests travel through microservices, helping teams find performance bottlenecks, trace the root cause of errors and analyse service dependencies. Its architecture consists of a collector, a query service and a web interface. It receives traces via the OpenTelemetry protocol (OTLP) over gRPC and HTTP and stores them in backends such as Elasticsearch, OpenSearch, Cassandra or ClickHouse. A Docker all-in-one image is available for trying it out, and production deployments are described in the documentation.
Jaeger was originally created by Uber and donated to the Cloud Native Computing Foundation (CNCF), where it graduated in October 2019. It is licensed under Apache 2.0 and governed openly by its maintainers. No vendor hosts the software or holds your data: you operate it yourself and choose where traces are stored, so a European organisation can keep all data on infrastructure in the EU. The trade-off is that you carry the operational work yourself.