Adding upstream version 1.34.4.

Signed-off-by: Daniel Baumann <daniel@debian.org>

docs/PROFILING.md

@@ -0,0 +1,57 @@
+# Profiling
+
+Telegraf uses the standard package `net/http/pprof`. This package serves via
+its HTTP server runtime profiling data in the format expected by the pprof
+visualization tool.
+
+## Enable profiling
+
+By default, the profiling is turned off. To enable profiling users need to
+specify the pprof address config parameter `pprof-addr`. For example:
+
+```shell
+telegraf --config telegraf.conf --pprof-addr localhost:6060
+```
+
+## Profiles
+
+To view all available profiles, open the URL specified in a browser. For
+example, open `http://localhost:6060/debug/pprof/` in your browser.
+
+To look at the heap profile:
+
+```shell
+go tool pprof http://localhost:6060/debug/pprof/heap
+```
+
+To look at a 30-second CPU profile:
+
+```shell
+go tool pprof http://localhost:6060/debug/pprof/profile?seconds=30
+```
+
+## Generate heap image
+
+It is very helpful to generate an image to visualize what heap memory is used.
+It is best to capture an image a few moments after Telegraf starts and then at
+additional periods (e.g. 1min, 5min, etc.).
+
+A user can capture the image with Go via:
+
+```shell
+go tool pprof -png http://localhost:6060/debug/pprof/heap > heap.png
+```
+
+The resulting image can be uploaded to a bug report.
+
+## References
+
+For additional information on pprof see the following:
+
+* [net/http/pprof][]
+* [Julia Evans: Profiling Go programs with pprof][]
+* [Debugging Go Code][]
+
+[net/http/pprof]: https://pkg.go.dev/net/http/pprof
+[julia evans: profiling go programs with pprof]: https://jvns.ca/blog/2017/09/24/profiling-go-with-pprof/
+[Debugging Go Code]: https://www.infoq.com/articles/debugging-go-programs-pprof-trace/