PROFILING.md

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:

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:

go tool pprof http://localhost:6060/debug/pprof/heap

To look at a 30-second CPU profile:

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:

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