max user processes
You are reaching the threads limit, for the user, process, or an overall limit
I had the same problem in a centOS/Red Hat machine. You are reaching the threads limit, for the user, process, or an overall limit
In my case there was a limit on the number of threads a user can have. Which can be checked with, the line saying max user processes
ulimit -a
You can see how many threads are running using this command
$ ps -elfT | wc -l
To get how many threads your process is running (you can get your process pid using top or ps aux):
$ ps -p
The /proc/sys/kernel/threads-max file provides a system-wide limit for the number of threads. The root user can change that value
To change the limits (in this case to 4096 threads):
$ ulimit -u 4096
java app with system.d
I recently stumbled over DefaultTasksMax which for some reason was limited to 60 on my machine – not enough for my new keycloak installation.
Keycloak crashes with java.lang.OutOfMemoryError : unable to create new native Thread as soon as it hits the ’60‘ limit (ps -elfT | grep keycloak|wc -l).
1. Look up your system.d settings
systemctl show --property DefaultTasksMax
In my case. This printed 60
2. Provide a higher value
editor /etc/systemd/system.conf
Edit:
DefaultTasksMax=128
You can also set a similar value TaskMax in your Unit-File.
3. Reload, Check, Restart
systemctl daemon-reload
systemctl show --property DefaultTasksMax
systemctl start keycloak