Overview
When you try to start or stop Apache you may see errors like "Error: Too many open files" and so file limit needs to be increased.
Procedure
On a server using systemd to manage services please follow the below steps.
Step 1 : Make directory as httpd.service.d under /usr/lib/systemd/system/
mkdir /usr/lib/systemd/system/httpd.service.dStep 2 : Now create a file with .conf extension like /usr/lib/systemd/system/httpd.service.d/limits.conf
touch /usr/lib/systemd/system/httpd.service.d/limits.confStep 3 : Now add the following content in limits.conf file like following:
[Service]
LimitNOFILE=40000Step 4 : Now reload daemon and restart httpd service.
systemctl daemon-reload
systemctl restart httpd
or
/usr/local/apps/apache2/bin/apachectl restartIf this limits.conf file changes does not work then you can directly modify /usr/local/apps/apache2/bin/apachectl and comment out the following lines of sections :
#if [ "x$ULIMIT_MAX_FILES" != "x" ] ; then
# $ULIMIT_MAX_FILES
#fiThen just after that commented section add following line with the limit needed:
ulimit -n 40000and you need to reload daemon and restart httpd service
systemctl daemon-reload
systemctl restart httpd
or
/usr/local/apps/apache2/bin/apachectl restartcheck the configured number of open files allowed for Apache2
First you need to get any one process ID that is running.
You can use ps to obtain the httpd process ID.
Run this command : ps auxw|grep -E '^USER|httpd'
You will have output like this :
root@server:~# ps auxw|grep -E '^USER|httpd'
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
root 2827484 0.0 2.0 378792 42036 ? Ss 09:40 0:00 /usr/local/apps/apache2/bin/httpd -k start
nobody 2831437 0.0 1.0 381472 21840 ? S 09:53 0:00 /usr/local/apps/apache2/bin/httpd -k start
nobody 2831438 0.0 1.0 381472 21840 ? S 09:53 0:00 /usr/local/apps/apache2/bin/httpd -k start
nobody 2831439 0.0 1.0 381472 21844 ? S 09:53 0:00 /usr/local/apps/apache2/bin/httpd -k start
nobody 2831440 0.0 1.0 381472 21260 ? S 09:53 0:00 /usr/local/apps/apache2/bin/httpd -k start
nobody 2831441 0.0 1.0 381608 21584 ? S 09:53 0:00 /usr/local/apps/apache2/bin/httpd -k start
nobody 2831443 0.0 1.0 381472 21840 ? S 09:53 0:00 /usr/local/apps/apache2/bin/httpd -k start
root 2834969 0.0 0.0 9032 660 pts/0 R+ 10:03 0:00 grep --color=auto -E ^USER|httpdNow using one of those pids you can get the limit setting from the pid proc files.
For example, taking pid 2827484 from the ps output above you can check with:
grep 'Max open files' /proc/2827484/limitsthe output it provides which shows the limit is set to 40000.
root@server:~# grep 'Max open files' /proc/2827484/limits
Max open files 40000 40000 files