jaegertracing/jaeger

Jaeger is a distributed tracing system, a tool for understanding what happens inside complex software systems made up of many services working together. When a user request flows through multiple services (for example, a web app that calls a database, an authentication service, and a payment processor), something can go wrong or be slow at any point. Tracing lets you follow that request's journey from start to finish and see exactly where time was spent or where errors occurred. The problem it solves: in traditional single-application software, debugging is straightforward, you look at one log file. In modern systems made of many interconnected services (called microservices), a single user action might touch dozens of services, and finding the source of a slowdown or failure is like tracking a package through a supply chain with no tracking number. Jaeger gives you that tracking number. How it works: your application code is instrumented (meaning small pieces of code are added) to record "spans", units of work with start times, end times, and metadata. These spans are sent to a Jaeger collector, which stores them. You can then use Jaeger's web UI to search for traces, visualize the full timeline of a request, and pinpoint which service caused a delay or error. You would use Jaeger when operating or debugging a system built from multiple services, especially one deployed with Kubernetes or similar infrastructure. The tech stack is Go, with OpenTelemetry support for instrumentation.