[2002] Three causes of MySQL socket errors and how to fix them

When connecting to a MySQL server from MySQL client software (mysql, PHP, Perl, etc.),

• MySQL server through socket '/tmp/mysql.sock '
• No such file or directory (trying to connect via unix : ///tmp/mysql . sock)

You may encounter an error like this and be unable to connect

This means
"Unable to connect to local MySQL server through socket /tmp/mysql.sock "

A socket is a Unix domain socket (file system socket), and when communicating within a local system,
communication between the server and client is carried out through file input and output.
It acts as an intermediary.

So, I would like to explain why this error occurs and how to deal with it

Cause of the error

Cause 1. The MySQL server is not running

$ ps aux | grep mysqld

Check if the process exists.
If not, start it.

$ sudo /etc/init.d/mysqld status 

Cause 2. The Unix socket path used by the MySQL server and the Unix socket path used by the client software are different

No such file or directory (trying to connect via unix:///tmp/mysql.sock)

For example, the error above shows that the client is looking at /tmp/mysql.sock , but
the MySQL server is looking at /var/lib/mysql/mysql.sock .

There are two solutions in this case:

Solution A. Match the client

If you look at the MySQL configuration file, /etc/my.cnf,

[mysqld] socket=/var/lib/mysql/mysql.sock

The path is written like this, so you just need to set the socket of the client software to the same path

Solution B. Match MySQL

Rewrite /etc/my.cnf as follows:

[mysqld] socket=same socket path as client [client] socket=same socket path as client [shell] After rewriting, restart MySQL. [shell]$ sudo /etc/init.d/mysqld restart

Cause 3. There is no socket file

There are two ways to solve this too

Solution A. Restart the MySQL server and it will be restored

(*This is a server restart, not a mysql restart.)

$ sudo shutdown -r now

Solution B. Create a socket file

Check your path by looking at /etc/my.cnf

$ touch /path/mysql.sock $ chown mysql:mysql /path/mysql.sock

Create a socket at that path and restart MySQL

$ sudo /etc/init.d/mysql restart

The above is the cause and solution of the MySQL 2002 error

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