Move sigdump gem to global dependencies
What does this MR do and why?
In !81111 (merged) we added sigdump
, a useful tool that traps SIGCONT
(configurable) to dump several useful data to a tmpfile:
- thread stack traces
- object space dump
- GC stats
This tool is useful for debugging live Rubies, so I think we should promote this to a global dependency.
It is a small pure Ruby tool, and is summarized in a single file: https://github.com/fluent/sigdump/blob/master/lib/sigdump.rb
My immediate use case outside of development was to debug Puma threads in a GKE cluster. In that environment we furthermore do not have access to rbtrace
, which makes it difficult to inspect Ruby VM state.
I think it is safe to use in production, bar any clashes with signal handling, though I do not think we use CONT
anywhere.
For added safety, I moved it behind an ENV var.
Example: sigdump-7.log
Closes #363832 (closed)
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