What about SIGTERM?

[hakavlad]

2018 will end soon, but the signal is still not supported.

[hakavlad]

I expect the follow behavior by default: 10% - SIGTERM, 5% - SIGKILL.

Code like this

if mem < sigkill_level:
    send_signal_to_viсtim(9)
elif mem < sigterm_level:
    send_signal_to_victim(15)
else:
    sleep()

[rfjakob]

Do you know an app that does something useful on SIGTERM?

[hakavlad]

I didn't understand what you meant. I know that most of apps accept SIGTERM and terminate correctly.

[rfjakob]

The disadvantage is that SIGTERM can be ignored by apps. What is the advantage?

[rfjakob]

I guess the idea is that the app does something like "clean up before shutdown". However, how long does that take? Does it need additional memory to do so?

[hakavlad]

It happens quickly in most cases. Even it will need additional memory, process will killed at 5% (for example). Also, user will can set thresholds like that: 10% for SIGKILL and 0% for SIGTERM for ignore SIGTERM.
SIGTERM used by full-featured OOM preventer and no any problem happens.

[rfjakob]

The thing is, this is an extra option that the user may have to think about.

earlyoom only uses sigkill and works fine!

[hakavlad]

extra option that the user may have to think about

Should I stop offer any features more?

[hakavlad]

extra option that the user may have to think about

I think that users are not idiots.

[rfjakob]

Should I stop offer any features more?

No, don't stop! I like several of them.

[rfjakob]

I am going through old tickets, and read this #34 again.

Apparently postgresql does something useful on SIGTERM. I'll think again about this.