Tag Archives: php

PHP_FPM of unix sockets vs TCP ports

When setup PHP-FPM for nginx pass_proxy, we may setup the php-fpm.conf include one of the config below:

listen = /var/run/php5-fpm.sock –> [nginx.conf] fastcgi_pass unix:/var/run/php5-fpm.sock;

listen = –> [nginx.conf] fastcgi_pass;

Performance of unix sockets vs TCP ports

When you are using TCP, you are also using the whole network stack. Even if you are on the same machine, this implies that packets are encapsulated and decapsulated to use the network stack and the related protocols.

If you use unix domain sockets, you will not be forced to go through all the network protocols that are required otherwise. The sockets are identified solely by the inodes on your hard drive.

Make PHP-FPM Listen at “IPAddress:Port” Instead of “/var/run/php5-fpm.sock;”

Sockets are slightly faster as compared to TCP/IP connection. But they are less scalable by default.

If you start getting errors like below

connect() to unix:/var/run/php5-fpm.sock failed or **apr_socket_recv: Connection reset by peer (104)**

Then it means you need to either switch to TCP/IP or tweak with linux-system parameter so that your OS can handle large number of connections.

So, for high-load cases this is what it’s supposed to be: listen = and that fixed everything!

Reference Links

Remove PHP X-Powered-By & Nginx Version

For some website’s security reason, we need remove X-Powered-By and NGINX Version from response headers.


To remove X-Powered-By completely, search line in php.ini.

expose_php = Off

or add the following directive to the Nginx configuration:

# Prevent version info leakage
fastcgi_hide_header X-Powered-By;


To remove Server Version from Header, server_tokens should be disabled in nginx.conf.

# http://wiki.nginx.org/HttpCoreModule#server_tokens
server_tokens off;

Change server string by recompiling Nginx source:

vim +49 src/http/ngx_http_header_filter_module.c

Find the lines:

static char ngx_http_server_string[] = "Server: nginx" CRLF;
static char ngx_http_server_full_string[] = "Server: " NGINX_VER CRLF;

see also: Customize Your Nginx Server Name After Compiling From Source