PHP-FPM requires restart to access generated file when visiting webpage - php

Question

As part of a web-based project I work on, we generate new "sites" which are accessed by passing in a different parameter to $_GET. All of the sites live in /usr/local/sites. None of the sites are owned (either user or group) by the user we use (hwphp, www-data is the default apache user still), but the user is in the group so can read all files in the directories.
I have a python script that generates sites and after running it, half the time when I try and visit it by going to http://localhost/index.php?site=newsite I get File not found: /var/local/sites/newsite/config/config.ini though running PHP CLI it can find the file and hwphp user can read it just fine, just when I go through PHP-FPM/Apache it fails.
Here's my pool configuration:
; Start a new pool named 'www'.
; the variable $pool can be used in any directive and will be replaced by the
; pool name ('www' here)
[submitty]
user = hwphp
group = hwphp
listen = /run/php/php7.0-fpm-submitty.sock
listen.owner = www-data
listen.group = www-data
;listen.mode = 0660
pm = dynamic
pm.max_children = 5
pm.start_servers = 2
pm.min_spare_servers = 1
pm.max_spare_servers = 3
and my apache configuration:
<VirtualHost 192.168.56.101:80>
AddDefaultCharset utf-8
ServerAdmin ADMIN#DOMAIN.HERE
ServerName 192.168.56.101
DocumentRoot /usr/local/submitty/site/public
DirectoryIndex index.html index.php index.htm index.cgi
SuexecUserGroup hwphp hwphp
<IfModule mod_fastcgi.c>
AddHandler php7-fcgi .php
Action php7-fcgi /php7-fcgi
Alias /php7-fcgi /usr/lib/cgi-bin/php7-fcgi
FastCgiExternalServer /usr/lib/cgi-bin/php7-fcgi -socket /var/run/php/php7.0-fpm-submitty.sock -pass-header Authorization
<FilesMatch ".+\.ph(p[345]?|t|tml)$">
SetHandler php7-fcgi
</FilesMatch>
<Directory /usr/lib/cgi-bin>
Require all granted
</Directory>
</IfModule>
<Files .*>
Order allow,deny
Deny from all
</Files>
<Files *~>
Order allow,deny
Deny from all
</Files>
<Files #*>
Order allow,deny
Deny from all
</Files>
<Directory />
AllowOverride None
</Directory>
<Directory /usr/local/submitty/site/public>
Require all granted
Order allow,deny
Allow from all
</Directory>
LogLevel error
ErrorLog ${APACHE_LOG_DIR}/submitty.log
CustomLog ${APACHE_LOG_DIR}/submitty.log combined
</VirtualHost>
as soon as I do:
service php7.0-fpm restart
and it works fine and the file is found. Not sure why this might be as it makes no sense (and why a simple restart is what fixes it).
Server is Ubuntu 16.04, using PHP 7 and Apache 2.4, everything from the stock apt-get installs.

Answer 1

The issue ended up being that PHP was doing some caching of the file read which was causing the issues when trying to open the files. Doing a restart of php-fpm flushed the cache and made things just work.