Hi,
Recently I got a trouble regarding php-fpm child process. Some process got stuck and make the CPU skyrocket to 100% after a few minutes. This is result when I'm using 'htop' command:

I've checked php log and see some errors too:

[04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "pkill: no matching criteria specified"
[04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "Try pkill --help' for more information." [04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "sh: 0: -c requires an argument" [04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "sh: 1: stratum+tcp: not found" [04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "pkill: no matching criteria specified" [04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "Trypkill --help' for more information."
[04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "sh: 0: -c requires an argument"
[04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "sh: 1: yam: not found"
[04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "pkill: no matching criteria specified"
[04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "Try pkill --help' for more information." [04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "sh: 0: -c requires an argument" [04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "sh: 1: xmrig: not found" [04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "pkill: no matching criteria specified" [04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "Trypkill --help' for more information."
[04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "sh: 0: -c requires an argument"
[04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "sh: 1: cryptonight: not found"
[04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "pkill: no matching criteria specified"
[04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "Try pkill --help' for more information." [04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "sh: 0: -c requires an argument" [04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "sh: 1: stratum+: not found" [04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "pkill: no matching criteria specified" [04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "Trypkill --help' for more information."
[04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "sh: 0: -c requires an argument"
[04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "sh: 1: donate-level: not found"
[04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "pkill: no matching criteria specified"
[04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "Try pkill --help' for more information." [04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "sh: 0: -c requires an argument" [04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "sh: 1: --max-cpu-usage: not found" [04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "pkill: no matching criteria specified" [04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "Trypkill --help' for more information."
[04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "sh: 0: -c requires an argument"
[04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "sh: 1: Syntax error: Unterminated quoted string"
[04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "sh: 1: Syntax error: Unterminated quoted string"
[04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "pkill: no matching criteria specified"
[04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "Try `pkill --help' for more information."
[04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "sh: 0: -c requires an argument"
[04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "sh: 1: Syntax error: Unterminated quoted string"
[04-Apr-2022 08:35:37] WARNING: [pool www-php74] child 18533 said into stderr: "sh: 0: Illegal option -- <

After a php service restart, everything back to normal, but after 5-10 minutes, random php process got stuck again.