(Optional) Configure limits.conf

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

If you are in a personal trial scenario, you can skip this step. If you are using it in a production environment, we recommend that you configure limits.conf.

You can modify resource limits at the global level by configuring the /etc/security/limits.conf file. The process-related limits for OceanBase Database include the maximum stack size per thread (Stack), the maximum number of open files (Open Files), and core file size (Core File Size).

Modify the configuration

Set the maximum stack 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:

[admin@test001 ~]$ 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

View the configuration

Log out of the current session and log in again. Run the following command to check if the configuration has taken effect.

[admin@test001 ~]$ 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 for core files (in blocks), corresponding to the core parameter in the limits.conf configuration file. Check if 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 if the value is 655350.

• stack size indicates the stack size in kilobytes. It corresponds to the stack parameter in the limits.conf configuration file. Check whether its value is unlimited.

• max user processes indicates the maximum number of user processes. It corresponds to the nproc parameter in the limits.conf configuration file. Check whether its value is 655360.