# package tracing `package tracing` provides [Dapper][]-style request tracing to services. ## Rationale Request tracing is a fundamental building block for large distributed applications. It's instrumental in understanding request flows, identifying hot spots, and diagnosing errors. All microservice infrastructures will benefit from request tracing; sufficiently large infrastructures will require it. ## OpenTracing Go kit builds on top of the [OpenTracing] API and uses the [opentracing-go] package to provide tracing middlewares for its servers and clients. Currently `kit/transport/http` and `kit/transport/grpc` transports are supported. Since [OpenTracing] is an upcoming standard API, Go kit should support a multitude of tracing backends. If a Tracer implementation in Go for your back-end exists, it should work out of the box. The following tracing back-ends are known to work with Go kit through the OpenTracing interface and are highlighted in the [addsvc] example. ### LightStep [LightStep] support is available through their standard Go package [lightstep-tracer-go]. ### AppDash [Appdash] support is available straight from their system repository in the [appdash/opentracing] directory. ### Zipkin [Zipkin] support is now available from the [zipkin-go-opentracing] package which can be found at the [Open Zipkin GitHub] page. This means our old custom `tracing/zipkin` package is now deprecated. In the `kit/tracing/zipkin` directory you can still find the `docker-compose` script to bootstrap a Zipkin development environment and a [README] detailing how to transition from the old package to the new. [Dapper]: http://research.google.com/pubs/pub36356.html [addsvc]:https://github.com/go-kit/kit/tree/master/examples/addsvc [README]: https://github.com/go-kit/kit/blob/master/tracing/zipkin/README.md [OpenTracing]: http://opentracing.io [opentracing-go]: https://github.com/opentracing/opentracing-go [Zipkin]: http://zipkin.io/ [Open Zipkin GitHub]: https://github.com/openzipkin [zipkin-go-opentracing]: https://github.com/openzipkin/zipkin-go-opentracing [Appdash]: https://github.com/sourcegraph/appdash [appdash/opentracing]: https://github.com/sourcegraph/appdash/tree/master/opentracing [LightStep]: http://lightstep.com/ [lightstep-tracer-go]: https://github.com/lightstep/lightstep-tracer-go