A.4.5. How to Protect or Change the MySQL Unix Socket File
The default location for the Unix socket file that the server
uses for communication with local clients is
/tmp/mysql.sock. (For some distribution
formats, the directory might be different, such as
/var/lib/mysql for RPMs.)
On some versions of Unix, anyone can delete files in the
/tmp directory or other similar directories
used for temporary files. If the socket file is located in such
a directory on your system, this might cause problems.
On most versions of Unix, you can protect your
/tmp directory so that files can be deleted
only by their owners or the superuser (root).
To do this, set the sticky bit on the
/tmp directory by logging in as
root and using the following command:
shell> chmod +t /tmp
You can check whether the sticky bit is set
by executing ls -ld /tmp. If the last
permission character is t, the bit is set.
Another approach is to change the place where the server creates
the Unix socket file. If you do this, you should also let client
programs know the new location of the file. You can specify the
file location in several ways:
-
Specify the path in a global or local option file. For
example, put the following lines in
/etc/my.cnf:
[mysqld]
socket=/path/to/socket
[client]
socket=/path/to/socket
See Section 4.3.2, “Using Option Files”.
Specify a --socket option on the command
line to mysqld_safe and when you run
client programs.
Set the MYSQL_UNIX_PORT environment
variable to the path of the Unix socket file.
Recompile MySQL from source to use a different default Unix
socket file location. Define the path to the file with the
--with-unix-socket-path option when you run
configure. See
Section 2.8.2, “Typical configure Options”.
You can test whether the new socket location works by attempting
to connect to the server with this command:
shell> mysqladmin --socket=/path/to/socket version
