Looks like that by default the mysql.sock file on OS X is stored under /tmp/. That causes problems wheh applications try to connect to the MySQL instance via /var/mysql/mysql.sock.
Quick solution: create symlink of /tmp/mysql.sock to /var/mysql/mysql.socn
: | : vortex of false deceit : | : 
/tmp/mysql.sock is the default location for sockets (in unix these are real sockets) for all unix OSes. Instead of it Linux machines prefer the /var/mysql/mysql.socn.
I would suggest you to keep the default. If your app fails to connect with mysql db, you could update the configuration file of your application. For example in RubyOnRails my configuration file seems like that:
production:
adapter: mysql
encoding: utf8
database: myprod_db
username: myuser
password: mypasswd
socket: /tmp/mysql.sock
The soft link it’s ok, but i think there is no need of it.
Vageli, thanks for the comment. I had a better look at the issue 🙂
I never had to setup MySQL on non-Linux machine before so I’d except things to just work. Linux though uses /var/lib/mysql/ for the socket location, not /var/mysql. Also, the default my.cnf configuration file on OS X (which I just realised has template files under /support-files) points to /tmp/mysql.sock. But looks like that the PHP configuration looks under /var/mysql/mysql.sock. I checked /etc/php.ini, the corresponding entry for the mysql socket was null and I changed that to /tmp/mysql.sock and then got it workig.
I wanted to install Drupal. I couldn’t see anywhere any options for defining the location of the socket and therefore I created the softlink (which I don’t think is of any harm). Changing the my.cnf to use /var/mysql/mysql.sock I’m afraid it may break other applications. Therefore it looks like that the best solution is to either change the configuration of the specification application, as you suggested, or alter the generic /etc/php.ini file.
Better yet, edit /etc/my.cnf (which won’t exist at first) and add the following four lines:
[client]
socket = /var/mysql/mysql.sock
[mysqld]
socket = /var/mysql/mysql.sock
Be sure to make /var/mysql/ owned by “_mysql” first, so mysql can write its socket there.
This is a good place to put it, because the built-in PHP has been compiled to look for that path.
Just wanted to verbalize my thanks for this entry. Your suggestions fixed my OS X / WordPress issue.
Thank you, thank you, thank you! I have been pissing around with this issue for the last 6+ hours. Editing /etc/php.ini.default didn’t work. Creating php.ini as a copy of php.ini.default and editing it didn’t work. Your symlink idea worked, hot damn!
I did have to make a new directory “mysql” in /var because it didn’t exist yet:
sudo mkdir /var/mysql
Then I could create the symbolic link inside that new mysql directory:
sudo ln -s /tmp/mysql.sock /var/mysql/mysql.sock
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Thanks everyone for posting about the /var/mysql/mysql.sock on OS X. I was able to use the info Jeremy posted. It worked great. Thanks again!
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