Linking dependencies ignores "nice" command and goes up to 100% CPU

[binarykitchen]

Do you want to request a feature or report a bug?
BUG

What is the current behavior?

nice -1 yarn --production still uses 100% of CPU. This when linking dependencies. My server is blocked for many minutes, even Postfix and all other mail traffic is down during that. Really bad. It should lower the priority based on nice -1 but nah, not happening.

Here an output, see my comment at end of line:

Your branch is up to date with 'origin/master'.
$ nice -1 yarn --production; gulp
[1/6] Validating package.json...
[2/6] Resolving packages...
[3/6] Fetching packages...
info @ffmpeg-installer/darwin-x64@4.1.0: The platform "linux" is incompatible with this module.
info "@ffmpeg-installer/darwin-x64@4.1.0" is an optional dependency and failed compatibility check. Excluding it from installation.
info @ffmpeg-installer/linux-ia32@4.1.0: The CPU architecture "x64" is incompatible with this module.
info "@ffmpeg-installer/linux-ia32@4.1.0" is an optional dependency and failed compatibility check. Excluding it from installation.
info @ffmpeg-installer/win32-ia32@4.1.0: The platform "linux" is incompatible with this module.
info "@ffmpeg-installer/win32-ia32@4.1.0" is an optional dependency and failed compatibility check. Excluding it from installation.
info @ffmpeg-installer/win32-ia32@4.1.0: The CPU architecture "x64" is incompatible with this module.
info @ffmpeg-installer/win32-x64@4.1.0: The platform "linux" is incompatible with this module.
info "@ffmpeg-installer/win32-x64@4.1.0" is an optional dependency and failed compatibility check. Excluding it from installation.
info @ffprobe-installer/darwin-x64@4.0.3: The platform "linux" is incompatible with this module.
info "@ffprobe-installer/darwin-x64@4.0.3" is an optional dependency and failed compatibility check. Excluding it from installation.
info @ffprobe-installer/linux-ia32@4.0.3: The CPU architecture "x64" is incompatible with this module.
info "@ffprobe-installer/linux-ia32@4.0.3" is an optional dependency and failed compatibility check. Excluding it from installation.
info @ffprobe-installer/win32-ia32@4.0.2: The platform "linux" is incompatible with this module.
info "@ffprobe-installer/win32-ia32@4.0.2" is an optional dependency and failed compatibility check. Excluding it from installation.
info @ffprobe-installer/win32-ia32@4.0.2: The CPU architecture "x64" is incompatible with this module.
info @ffprobe-installer/win32-x64@4.0.2: The platform "linux" is incompatible with this module.
info "@ffprobe-installer/win32-x64@4.0.2" is an optional dependency and failed compatibility check. Excluding it from installation.
info fsevents@1.2.4: The platform "linux" is incompatible with this module.
info "fsevents@1.2.4" is an optional dependency and failed compatibility check. Excluding it from installation.
[4/6] Linking dependencies... <------------ here CPU is at 100% for many minutes !!!
...

What is the expected behavior?
During yarn install for production, server should still have some CPU left, able to run all other background processes and isn't blocking email traffic.

Please mention your node.js, yarn and operating system version.

└─❱❱❱ yarn --version
1.12.3

└─❱❱❱ node --version
v8.12.0

Server runs on Ubuntu 18.10

[Daniel15]

It should lower the priority based on nice -1

Negative numbers actually increase the priority 😛 Try using a positive number and see if that helps.

Also, AFAIK nice only affects the kernel's CPU scheduler. The kernel decides to give less CPU time to a process that has a higher niceness value. The actually app doesn't change its behaviour as a result of its niceness value changing.

[binarykitchen]

Oh lol ... I better study the nice command over again. Any recommendations what number to pick? Or do you know a better trick or command?

[Daniel15]

Check the Wikipedia page (https://en.wikipedia.org/wiki/Nice_(Unix)) as well as the manpage (https://linux.die.net/man/1/nice or run man nice on your system).

Any recommendations what number to pick?

19 is the lowest priority... Basically everything else on the system takes priority over it, and it only gets CPU power / IO if nothing else needs it. Good for background jobs like backups (my nightly automated backups use nice 19). Apart from that I don't really have much advice around it - Maybe someone else has better advice 😄

[binarykitchen]

15 works a bit better, doesn't block my server that much anymore. But I guess that during linking other processes are being called, i.E. ffmpeg compilation (see my output above). Wondering if the nice command is passing on the nicety to the child processes it's spawning?

On a side note, I also wonder if yarn itself should have some code or countermeasures to prevent this from happening? This on any server.