fileDescriptorLimit could not set according to system default value

[SyinChwunLeo]

Expected behaviour

when packaging, sbt-native-packager will use default value of fileDescriptorLimit or use user defined. If is it possible to use the ulimit value of app running machine?

for example, I package using the default value (1024), but the app running machine is 100000, when I check /proc/PID/limits, the "Max open files" is 1024, not 100000.

If I set a fixed value, the app will run on different machines, and their system "max open files" are different. Maybe it is unreasonable to use a fixed value when packaging

[muuki88]

Thanks for your issue 😀
Can you add some information?

• which OS you are running the application
• which native-packager version are you using
• how is the app starred ( systemd, systemV, upstart, .. )

I'm not aware that native-packager scripts mess with any file limit settings.

[SyinChwunLeo]

• I run the application on CentOS 7 and set configurations in /etc/security/limits.conf as follows:

*  soft   nofile    1000000
*  hard  nofile     1000000

and using ulimit -Hn  or ulimit -Sn command return 1000000.    

• My sbt-native-packager is version 1.2.0

 addSbtPlugin("com.typesafe.sbt" % "sbt-native-packager" % "1.2.0") 

• I use systemd

enablePlugins(RpmPlugin, JavaServerAppPackaging, SystemdPlugin)

• When I do not use fileDescriptorLimit := Some("1000000") this configuration, the Max open files is 1024 (this is the default value https://github.com/sbt/sbt-native-packager/blob/master/src/main/scala/com/typesafe/sbt/packager/linux/LinuxPlugin.scala line 78) When using fileDescriptorLimit := Some("1000000"), Max open files is 1000000.
• app's Max open files can be found by cat /proc/PID/limits.

[muuki88]

Thanks for the more detailed explanation 😄

At the moment we don't have conditional template replacements. This is the systemd template that renders the systemd service conf. Is there a "magic" value that says "use system default"?

I haven't had any issue with file descriptor limits. What's the use case for making this limit not application specific?

[SyinChwunLeo]

I catch this case by a bug, In our application, HttpClient jar is used to call RESTFUL API, unfortunately， after running period of time, app throws "too many files open" exception.

[muuki88]

Thanks for sharing 🤗

I guess then there's no need to configure this in another way, right?

[SyinChwunLeo]

maybe

[tolikr]

Systemd ignores limits from places like limits.conf.
https://serverfault.com/questions/628610/increasing-nproc-for-processes-launched-by-systemd-on-centos-7