On a cpanel server webmail is down and keep getting email from cpanel server saying cpanel_php_fpm failed.

On checking cpanel php-fpm log, have following error

root@server74 [~]# tail /usr/local/cpanel/logs/php-fpm/error.log 
[14-Mar-2017 06:01:49] ERROR: [pool user_yesudas] unable to create child_accept_pipe
[14-Mar-2017 06:01:49] ERROR: [pool user_yoifound] unable to create child_accept_pipe
[14-Mar-2017 06:01:49] ERROR: [pool user_yujinbob] unable to create child_accept_pipe
[14-Mar-2017 06:01:49] ERROR: [pool user_zajgroup] unable to create child_accept_pipe
[14-Mar-2017 06:01:49] ERROR: [pool user_zamzamt] unable to create child_accept_pipe
[14-Mar-2017 06:01:49] ERROR: [pool user_zeemaxx] unable to create child_accept_pipe
[14-Mar-2017 06:01:49] ERROR: [pool user_zerobeco] unable to create child_accept_pipe
[14-Mar-2017 06:01:49] NOTICE: ready to handle connections
[14-Mar-2017 06:01:49] ERROR: failed to prepare the stdout pipe: Too many open files (24)
[14-Mar-2017 06:01:49] ERROR: failed to prepare the stdout pipe: Too many open files (24)
root@server74 [~]# 

Problem is fixed by editing file

vi /var/cpanel/php-fpm.d/rlimit.conf

Add

[global]
rlimit_files = 4096

Now restart php-fpm service

/scripts/restartsrv_cpanel_php_fpm --stop
/scripts/restartsrv_cpanel_php_fpm --start