Re: ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)

[Dennis Yu]

I use SuSE SLES9, it was included 4.0.18 but I removed all and installed 5.0.22 RPM.
When just completed RPM installation, there's no my.cnf in /etc, at this time, if MySQL started at boot time (thru /etc/init.d/mysql start), or manually thru mysqld_safe, it will create /var/lib/mysql/mysql.sock and /var/lib/mysql/sles9.pid (my server named sles9) files. If your use "mysqladmin -p shutdown" (I have password for root), you'll see these 2 files disappeared.
Then I copied /usr/share/mysql/my-large.cnf to /etc/my.cnf without any change of its content, use mysqld_safe restarted MySQL, server is started but there's no /var/lib/mysql/mysql.sock file. If I use TCP/IP connection (mysql -h 127.0.0.1 -u root -p) still can connect to local MySQL server. Later checked reference manual chapter 5, I stopped server, added [mysql.server] and [mysqld_safe] sections in my.cnf above [mysqld] section, put :
socket=/var/lib/mysql/mysql.sock
pid-file=/var/lib/mysql/sles9.pid
then everything become normal after restarted with mysqld_safe. My conclusion:
1) There're only 2 ways to start/stop MySQL server, "/etc/init.d/mysql start" and "mysqld_safe".
2) If want to pass variables to any of above, must put exactly in its section in my.cnf
3) MySQL started at host boot time, it uses "/etc/init.d/mysql start", if later stopped and restarted with "mysqld_safe", the sections [mysql.server] and [mysqld_safe] must contain same contents, otherwise will result differently.
4) carefully study reference manual chapter 5 is needed and greatly helped.



Edited 1 time(s). Last edit at 07/17/2006 07:07AM by Dennis Yu.