Configure limits.conf

This topic describes how to limit the number of processes by configuring limits.conf.

If you are a personal user, you can skip this step. If you are an enterprise user, it is recommended to configure limits.conf.

You can modify resource limits using the following method:

Modify at the global level through the configuration file /etc/security/limits.conf.

The limits involved in seekdb processes include the maximum stack space size, maximum number of open files, and core file size.

Modify configuration

Set the maximum stack space size at the session level to unlimited, the maximum number of open files to 655350, and the core file size to unlimited.

Run the following command to open the /etc/security/limits.conf configuration file:

sudo vim /etc/security/limits.conf

Add the following content to the /etc/security/limits.conf configuration file:

* soft nofile 655350
* hard nofile 655350
* soft stack unlimited
* hard stack unlimited
* soft nproc 655360
* hard nproc 655360
* soft core unlimited
* hard core unlimited

info

• You need to check whether the nproc configuration exists in the /etc/security/limits.d/20-nproc.conf file. If it exists, you need to synchronously modify the nproc value in that file.
• The limits.conf configuration only takes effect for newly logged-in sessions (such as newly opened terminals, SSH connections, or newly started processes). Existing sessions or processes will not automatically inherit the new configuration and need to log in again or restart related services.

View configuration

Exit the current session and log in again. Run the following command to check whether the configuration has taken effect.

ulimit -a

The output is as follows.

core file size          (blocks, -c) unlimited
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 252876
max locked memory       (kbytes, -l) 64
max memory size         (kbytes, -m) unlimited
open files                      (-n) 655350
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) unlimited
cpu time               (seconds, -t) unlimited
max user processes              (-u) 655360
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

From the results, you can see:

• Core file size indicates the maximum threshold of core files (in blocks), corresponding to the core parameter in the limits.conf configuration file. Check whether the value is unlimited.

• Open files indicates the maximum number of open file descriptors, corresponding to the nofile parameter in the limits.conf configuration file. Check whether the value is 655350.

• Stack size indicates the stack size (in kilobytes), corresponding to the stack parameter in the limits.conf configuration file. Check whether the value is unlimited.

• Max user processes indicates the maximum number of user processes, corresponding to the nproc parameter in the limits.conf configuration file. Check whether the value is 655360.