Ruby on Rails 3 Can't connect to local MySQL server through socket '/tmp/mysql.sock' on OSX

I have a standard Rails3 environment, RVM 1.2.9, Rails 3.0.5, Ruby 1.9.2p180, MySQL2 Gem 0.2.7, mysql-5.5.10-osx10.6-x86_64

Error I get when running rake db:migrate to create database is:

Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)

config/database.yml has

development:
  adapter: mysql2
  host: localhost
  username: root
  password: xxxx
  database: xxxx

sure it's something simple I'm missing.

First, to find your socket file:

mysqladmin variables | grep socket

For me, this gives:

| socket                                            | /tmp/mysql.sock                                                                                                        |

Then, add a line to your config/database.yml:

development:
  adapter: mysql2
  host: localhost
  username: root
  password: xxxx
  database: xxxx
  socket: /tmp/mysql.sock

Found it!

Change host: localhost in config/database.yml to host: 127.0.0.1 to make rails connect over TCP/IP instead of local socket.

development:
  adapter: mysql2
  host: 127.0.0.1
  username: root
  password: xxxx
  database: xxxx

Your mysql server may not be running. Below explains how to start the server. This is an excerpt from the README file that comes with the mysql download.

After the installation, you can start up MySQL by running the following commands in a terminal window. You must have administrator privileges to perform this task.

If you have installed the Startup Item, use this command:

 shell> sudo /Library/StartupItems/MySQLCOM/MySQLCOM start
 (ENTER YOUR PASSWORD, IF NECESSARY)
 (PRESS CONTROL-D OR ENTER "EXIT" TO EXIT THE SHELL)

If you don't use the Startup Item, enter the following command sequence:

 shell> cd /usr/local/mysql
 shell> sudo ./bin/mysqld_safe
 (ENTER YOUR PASSWORD, IF NECESSARY)
 (PRESS CONTROL-Z)
 shell> bg
 (PRESS CONTROL-D OR ENTER "EXIT" TO EXIT THE SHELL)

These are options to fix this problem:

Option 1: change you host into 127.0.0.1

staging:
  adapter: mysql2
  host: 127.0.0.1
  username: root
  password: xxxx
  database: xxxx
  socket: your-location-socket

Option 2: It seems like you have 2 connections into you server MySql. To find your socket file location do this:

mysqladmin variables | grep socket

for me gives:

mysqladmin: connect to server at 'localhost' failed
error: 'Can't connect to local MySQL server through socket '/Applications/XAMPP/xamppfiles/var/mysql/mysql.sock' (2)'
Check that mysqld is running and that the socket: '/Applications/XAMPP/xamppfiles/var/mysql/mysql.sock' exists!

or

mysql --help 

I get this error because I installed XAMPP in my OS X Version 10.9.5 for PHP application. Choose one of the default socket location here.

I choose for default rails apps:

socket: /tmp/mysql.sock

For my PHP apps, I install XAMPP so I set my socket here:

socket: /Applications/XAMPP/xamppfiles/var/mysql/mysql.sock

OTHERS Socket Location in OS X

For MAMPP:

socket: /Applications/MAMP/tmp/mysql/mysql.sock

For Package Installer from MySQL:

socket: /tmp/mysql.sock

For MySQL Bundled with Mac OS X Server:

socket: /var/mysql/mysql.sock

For Ubuntu:

socket: /var/run/mysqld/mysql.sock

Option 3: If all those setting doesn't work you can remove your socket location:

staging:
  # socket: /var/run/mysqld/mysql.sock

I hope this help you.

"/tmp/mysql.sock" will be created automatically when you start the MySQL server. So remember to do that before starting the rails server.

With my installation of MAMP on OSX the MySQL socket is located at /Applications/MAMP/tmp/mysql/mysql.sock. I used locate mysql.sock to find my MySQL socket location.

So my config/database.yml looks like:

development:
  adapter: mysql2
  host: localhost
  username: root
  password: xxxx
  database: xxxx
  socket: /Applications/MAMP/tmp/mysql/mysql.sock

If you are on Mac OSX,

> The default location for the MySQL Unix socket is different on Mac OS X and Mac OS X Server depending on the installation type you chose

MySQL Unix Socket Locations on Mac OS X by Installation Type

• Package Installer from MySQL ------------------/tmp/mysql.sock

---

• Tarball from MySQL -------------------------------/tmp/mysql.sock

---

• MySQL Bundled with Mac OS X Server -------/var/mysql/mysql.sock

So just change your database.yml in socket: /tmp/mysql.sock to point to the right place depending on what OS and installation type you are using

The default location for the MySQL socket on Mac OS X is /var/mysql/mysql.sock.

I have had the same problem, but none of the answers quite gave a step by step of what I needed to do. This error happens because your socket file has not been created yet. All you have to do is:

1. Start you mysql server, so your /tmp/mysql.sock is created, to do that you run: mysql server start
2. Once that is done, go to your app directory end edit the config/database.yml file and add/edit the socket: /tmp/mysql.sock entry
3. Run rake:dbmigrate once again and everything should workout fine

I found that the problem is that I only have a production environment. I do not have a development or test environment.

By adding 'RAILS_ENV=production' to give the command

bundle exec rake redmine:plugins:migrate RAILS_ENV=production

it worked

If you are running MYSQL through XAMPP:

1. Open XAMPP mysql configuration file (on OSX):

   /Applications/XAMPP/etc/my.cnf

2. Copy the socket path:

   socket = /Applications/XAMPP/xamppfiles/var/mysql/mysql.sock

3. Open rails project's database configuration file: myproject/config/database.yml

4. Add the socket config to the development database config:

-->

development:
  adapter: mysql2
  encoding: utf8
  reconnect: false
  database: difiuri_falcioni
  pool: 5
  username: root
  password:
  host: localhost
  socket: /Applications/XAMPP/xamppfiles/var/mysql/mysql.sock

5. Restart rails server

Enjoy :)

You have problem with like this: Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock'

Ans: $ sudo service mysql start

On my machine mysqld service stopped that's why it was giving me the same problem.

1:- Go to terminal and type

sudo service mysqld restart

This will restart the mysqld service and create a new sock file on the required location.

If you are running MYSQL through XAMPP or LAMPP on Ubuntu or other Linux, try:

socket: /opt/lampp/var/mysql/mysql.sock