Home » Mysql » localhost vs. 127.0.0.1

localhost vs. 127.0.0.1

Posted by: admin November 1, 2017 Leave a comment

Questions:
  1. Does using localhost in mysql_connect() make the connection faster than using 127.0.0.1?
  2. What is the connection type between the PHP script and mySQL (when using the mysql_connect() function) ? Is it TCP/IP?
Answers:
  1. Differs between Windows and Linux. If you use a unix domain socket it’ll be slightly faster than using TCP/IP (because of the less overhead you have).
  2. Windows is using TCP/IP as a default, whereas Linux tries to use a Unix Domain Socket if you choose localhost and TCP/IP if you take 127.0.0.1.
Questions:
Answers:

“localhost” means local socket connection while 127.0.0.1 is TCP/IP. And yes, sockets are faster than TCP/IP.

Cite from http://pl.php.net/mysql_connect

Whenever you specify “localhost” or “localhost:port” as server, the MySQL client library will override this and try to connect to a local socket (named pipe on Windows). If you want to use TCP/IP, use “127.0.0.1” instead of “localhost”. If the MySQL client library tries to connect to the wrong local socket, you should set the correct path as in your PHP configuration and leave the server field blank.

Questions:
Answers:

Nope, the 127.0.0.1 is recommended to use , because Windows 7 has a problem with choosing between IPv6 & IPv4. I tried this and if I used localhost, the page has reloading about 1sec (1,04sec) and when i used 127.0.0.1, the page has reloading 50ms. Both were used under Windows 7.
In Windows XP it doesn´t make difference.

Questions:
Answers:

Php site says:

Note:

Whenever you specify “localhost” or
“localhost:port” as server, the MySQL
client library will override this and
try to connect to a local socket
(named pipe on Windows). If you want
to use TCP/IP, use “127.0.0.1” instead
of “localhost”. If the MySQL client
library tries to connect to the wrong
local socket, you should set the
correct path as in your PHP
configuration and leave the server
field blank.

I guess the speed difference would be too low that it’s something you should’nt be worried about.

Questions:
Answers:

For Unix, add to the client block after
[client]
in /etc/mysql/my.cnf this line :

protocol=tcp

Questions:
Answers:

For macs, here’s the solution:

Connect to MySQL using localhost instead of 127.0.0.1 on a MAC. For a long while now I’ve been connecting to MySQL on my development platform with 127.0.0.1 because for some reason localhost didn’t work. Turns out it’s because 127.0.0.1 uses TCP/IP and localhost uses sockets. The php.ini file points to the wrong place for the mysql.sock so all you have to do is change it, restart apache and voila!

Open php.ini: /private/etc/php.ini
Find the following line: mysql.default_socket = /var/mysql/mysql.sock
Replace with: mysql.default_socket = /tmp/mysql.sock
Restart apache: apachectl restart

Note: If you don’t have a php.ini file, you need to copy the provided default called php.ini.default

sudo cp /private/etc/php.ini.default /private/etc/php.ini

via http://madproject.com/general/connect-to-mysql-using-localhost-instead-of-127-0-0-1-on-a-mac/