srv provides a /startupz route on :8081 that will become active the instant srv.New is called. It will respond with 503 Service Unavailable until srv.Start() has completed instrumentation and starting any jobs. Thereafter it will respond with 200 OK.

srv provides a very basic readiness handler at /readyz that will start responding after the call to srv.Start(). The route simply responds with 200 and OK as the response body to every request. It will never explicitly fail, with the reasoning being that if your service is so busy that it can't respond to such a simple request in whatever timeout you deem appropriate then it isn't "ready".

Readiness handlers can cause

• Leadership
• https://github.com/felixge/fgprof