Description:
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Hi
In my servers there are 3 php version: 5.4.40, 5.5.24 and 5.6.8. All versions use FPM. My Apache version is 2.4.12 with mpm event. The problem is: 
A test with the standard wordpress, if I have many hits does not consume the maximum processing machine or memory but is giving problems or slowdowns. And one hour, it's 503 error but does not return, I need to restart the service fpm. Even without many hits keep dropping and returning the site and stabilizes only restarting the service. This in any version of PHP. This problem did not exist in the older version we were using.
##################################
pool configuration

[POOL_NAME]
listen = 127.0.0.1:9014
listen.allowed_clients = 127.0.0.1
user = USER
group = GROUP
pm = ondemand
pm.max_children = 15
pm.start_servers = 1
pm.min_spare_servers = 2
pm.max_spare_servers = 3
pm.max_requests = 2000
request_terminate_timeout = 10m
pm.process_idle_timeout = 10m
##################################
Apache configuration

KeepAlive On
MaxKeepAliveRequests    500
KeepAliveTimeout        15
Timeout                 300
GracefulShutdownTimeout 2

<IfModule event.c>
StartServers 1
ServerLimit 5
MinSpareThreads 25
MaxSpareThreads 100
ThreadsPerChild 200
ThreadLimit 200
MaxRequestWorkers 1000
MaxConnectionsPerChild 10000000
</IfModule>
##################################
VirtualHost configuration

<Proxy fcgi://127.0.0.1:9014>
ProxySet timeout=300
ProxySet disablereuse=off
</Proxy>
<FilesMatch \.php$>
SetHandler "proxy:fcgi://127.0.0.1:9014"
</FilesMatch>

FPM LOG
DEBUG: pid 167075, fpm_children_make(), line 421: [pool POOL_NAME] child 167108 started
DEBUG: pid 167075, fpm_pctl_on_socket_accept(), line 536: [pool POOL_NAME] got accept without idle child available .... I forked
DEBUG: pid 167075, fpm_event_loop(), line 419: event module triggered 1 events

Test script:
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Expected result:
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Actual result:
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