PHP70-FPM ERRO: não foi possível ler o que uma criança disse: Descritor de arquivo incorreto (9)

Question

Recebo continuamente os seguintes erros nos meus php-fpm logs. Eu li e tentei alguma pergunta semelhante disponível no serverfault.com, mas o problema não foi resolvido.

[11-Apr-2017 08:33:27] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 09:49:26] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 09:49:26] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 09:56:11] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 09:56:11] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 10:09:56] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 10:09:56] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 10:22:39] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 10:22:39] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 10:35:52] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 10:35:52] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 10:38:52] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 10:46:33] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 10:46:33] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 10:54:21] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 10:54:21] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 10:59:17] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 11:03:16] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 11:03:16] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 11:05:50] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 11:05:50] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 11:05:50] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 11:05:50] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 11:12:03] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 11:32:45] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 11:32:45] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 11:48:28] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 11:48:28] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 11:53:11] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 11:55:15] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 11:55:15] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 12:06:17] ERROR: unable to read what child say: Bad file descriptor (9)
[11-Apr-2017 12:06:17] ERROR: unable to read what child say: Bad file descriptor (9)

Meu sistema operacional é o CentOS7 e estou usando PHP7-FPM com nginx

Especificação do servidor está abaixo

Processador: Intel Xeon E5-1620v2

Sever Ram: 64 GB DDR3

Minhas configurações atuais de fpm estão abaixo

pid = /run/plesk-php70-fpm.pid

error_log = /var/log/plesk-php70-fpm/error.log

log_level = error

emergency_restart_threshold = 10
emergency_restart_interval = 1m
process_control_timeout = 10s

listen.backlog = 65535

;[php-fpm-pool-settings]
pm = ondemand
pm.max_children = 2000
pm.process_idle_timeout = 10s
#pm.max_requests = 10000

#pm = dynamic
#pm.max_children = 5000
#pm.start_servers = 50
#pm.min_spare_servers = 20
#pm.max_spare_servers = 70
#pm.max_requests = 10000

Eu tentei pm ondemand & pm dynamic both