Provide option to ignore SIGCONT

[jregovic]

Is your feature request related to a problem? Please describe.

When running under systemd, fluentd will produce a sigdump file even when a normal exit occurs.

Systemd sends a SIGCONT tot he process after the SIGTERM, which causes the sigdump file to be generated, putting unnecessary files in /tmp

Describe the solution you'd like

An option in the fluentd config file to disable producing sigdump files

Describe alternatives you've considered

We have adjusted settings for our systemd unit file, but systemd always sends the sigcont.

Additional context

No response

[abetomo]

I think disabling SIGCONT handler after SIGTERM will solve the problem.
(Suggested changes: #4034)

1. Add option to disable sigdump
2. Disable SIGCONT handler after SIGTERM
3. Both 1 and 2

Which is better: 1, 2, or 3?

[ashie]

Thanks for the fix!
I think 2 is enough for addressing the issue.

We'll consider adding 1 if someone really requires it, but I think it's not needed for now.

[daipom]

Thanks for the fix!
I will see it soon!

[daipom]

Note

https://www.freedesktop.org/software/systemd/man/systemd.kill.html#KillSignal=

right after sending the signal specified in this setting, systemd will always send SIGCONT, to ensure that even suspended tasks can be terminated cleanly.

So, for example, in td-agent, SIGCONT is sent after SIGTERM when stopping.

https://github.com/fluent/fluent-package-builder/blob/v4.4.2/td-agent/templates/etc/systemd/td-agent.service.erb#L28

[daipom]

I too think 2 is preferable for now.