When trying to access PHP-FPM's status monitoring page, receiving a "File not found" error typically indicates configuration mismatches between your PHP-FPM setup and web server. Let's examine how to properly configure this essential monitoring feature.

First, check your existing PHP-FPM pool configuration for status paths:

# Check status and ping paths in PHP-FPM config
grep -ER "status|ping" /etc/php5/* | grep -v ":;"

# Expected output should show:
/etc/php5/fpm/pool.d/www.conf:pm.status_path = /status
/etc/php5/fpm/pool.d/www.conf:ping.path = /ping
/etc/php5/fpm/pool.d/www.conf:ping.response = pong

When testing directly via fcgi, we need proper environment variables:

# Correct way to test status page via fcgi
SCRIPT_NAME=/status \
SCRIPT_FILENAME=/status \
QUERY_STRING=full \
REQUEST_METHOD=GET \
cgi-fcgi -bind -connect /var/run/php-fpm-www.sock

# For ping test:
SCRIPT_NAME=/ping \
SCRIPT_FILENAME=/ping \
REQUEST_METHOD=GET \
cgi-fcgi -bind -connect /var/run/php-fpm-www.sock

For Nginx, you need proper location block configuration:

location ~ ^/(status|ping)$ {
    access_log off;
    allow 127.0.0.1;
    deny all;
    include fastcgi_params;
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    fastcgi_pass unix:/var/run/php-fpm-www.sock;
}

For Apache with mod_proxy_fcgi:

<Location /status>
    SetHandler "proxy:unix:/var/run/php-fpm-www.sock|fcgi://localhost"
    ProxySet enablereuse=on
</Location>

• Permission Issues: Ensure your web server user has access to the PHP-FPM socket file
• Path Mismatches: Verify pm.status_path matches exactly in both PHP-FPM and web server config
• PHP-FPM Restart Needed: Always restart PHP-FPM after configuration changes
• Output Format: Add ?json, ?html, or ?full to the status URL for different output formats

You can customize what information appears in the status page:

; In php-fpm pool configuration
pm.status_path = /status
; Available options: full, html, json
; Example URL: http://yourserver/status?json

Remember that the status page can reveal sensitive information about your server, so always restrict access to trusted IPs only.

When attempting to access PHP-FPM's status monitoring page, you're encountering a 404 error despite having the configuration properly set. This occurs both through browser requests and direct FastCGI connections.

# Current configuration verification
grep -ER "status|ping" /etc/php5/* | grep -v ":;"
/etc/php5/fpm/pool.d/www.conf:pm.status_path = /status
/etc/php5/fpm/pool.d/www.conf:ping.path = /ping
/etc/php5/fpm/pool.d/www.conf:ping.response = pong

The "Primary script unknown" error typically indicates one of these scenarios:

• Nginx/Apache isn't properly configured to handle the FastCGI pass
• PHP-FPM doesn't have permissions to access the status path
• Missing allow directive in PHP-FPM pool configuration
• The socket connection isn't properly established

For Nginx servers, you'll need this location block:

location ~ ^/(status|ping)$ {
    access_log off;
    allow 127.0.0.1;
    deny all;
    include fastcgi_params;
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    fastcgi_pass unix:/var/run/php-fpm-www.sock;
}

For PHP-FPM pool configuration (/etc/php5/fpm/pool.d/www.conf):

pm.status_path = /status
ping.path = /ping
ping.response = pong

; Restrict access
listen.allowed_clients = 127.0.0.1

To test the FastCGI interface directly (bypassing web server):

# For status page
SCRIPT_NAME=/status SCRIPT_FILENAME=/status REQUEST_METHOD=GET \
cgi-fcgi -bind -connect /var/run/php-fpm-www.sock

# For ping endpoint
SCRIPT_NAME=/ping SCRIPT_FILENAME=/ping REQUEST_METHOD=GET \
cgi-fcgi -bind -connect /var/run/php-fpm-www.sock

On RedHat-based systems with SELinux:

# Check SELinux context
ls -Z /var/run/php-fpm-www.sock

# Temporary allow HTTPD to connect
setsebool -P httpd_can_network_connect 1

If you still can't access via web server, try these alternatives:

# Using curl through localhost
curl "http://localhost/status?json"

# Using socat for raw socket communication
echo -e "GET /status HTTP/1.0\r\n\r\n" | socat unix-connect:/var/run/php-fpm-www.sock -