pprof

Damn I hate it when you write a whole project and someone comes along and says "this already exists" and you realise how much time you wasted (yeah even if some of it counts towards learning I'd still rather not needlessly repeat other people's work). Anyway, pprof has a fantastic interactive Flamegraph viewer that lets you narrow down to specific functions. It's really very good, I would use that. https://github.com/google/pprof Run `pprof -http=:` on a profile and you get a web interface with the Flamegraph, call graph, line based profiling etc. It's demonstrated in this video. https://youtu.be/v6skRrlXsjY They only show a very simple example and no zooming, but it works very well with huge flamegraphs.

How do flame graphs handle the case where most of the time is spent in some leaf function that is called from all over the program? In this case, each individual stack would not take much time but in aggregate, a lot of time is spent in the function at the top of all of the call stacks. This should not be that uncommon to have hotspots in things like copying routines, compression, encryption etc that are not associated with any particular stack. pprof from https://github.com/google/pprof can produce a DAG view of a profile where nodes are sized proportional to their cumulative time, e.g., https://slcjordan.github.io/images/pprof/graphviz.png and such a view would seem to cover the case above and subsume the usual use cases for a flame graph, would it not? Although I guess a flat text profile of functions sorted by time would also highligh

The pprof format is not tied to Go. From my understanding, it's used within Google across multiple languages. The format is defined in the pprof repository[0], and the visualization tool is source-language agnostic. I've seen libraries in numerous languages (e.g. Python, Java) to publish profiles in pprof format. This is an indicator the pprof format has become de-facto. Grafana Pyroscope[1] is a tool that's capable of parsing the pprof format, agnostic to the source programming language, and has instructions for Go, Java, Python, Ruby, node.js, Rust, and .NET. My understanding is that you're searching for a combination of the profiles, metrics, and tracing. Caddy supports all 3. [0] https://github.com/google/pprof/blob/main/doc/README.md [1] https://grafana.com/docs/pyroscope/latest/ metrics and tracing need to be manually enabled (for