Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)

The title of this post was the most bugging error for me while working with MySQL on Linux. I installed MySQL Server 5.6 on my Ubuntu system manually. Then I installed and configured MySQL Workbench. Then I restarted my system. When I tried to connect to MySQL Server through command line, I got the error,

Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)

This means the service MySQL is not running on system and it has to be started. So I tried starting the server with the following command,

shell> sudo /usr/local/mysql/support-files/mysql.server start

Then I got a new error,

couldn't find mysql server (/usr/bin/mysqld_safe)

I understood that it is looking a wrong directory for mysqld_safe because I installed in another location. This can be set in the file my.cnf. It is located in the folder /etc/mysql/. I went to that location and changed the base directory and data directory locations in that file and attempted to start the server, but it was of no use.

I surfed a lot to find a solution for this problem but no blog suggested me the right one. May be, my search was wrong. Some blogs suggested to check whether the directory mysqld exists in the location /var/run/ so that the socket file mysqld.sock can be created while starting the server. Following this suggestion, I created a directory in the location /var/run/ with the name mysqld. Then I tried to start the service and it resulted in a new error,

Starting MySQL... ERROR! The server quit without updating PID file

I didn't know what to do with this error. I searched online for its solution. Many blogs suggested me to kill the process with the name mysql but it didn't help me. Getting frustrated, I removed and re-installed MySQL multiple times on my system. But nothing was fruitful.

Then I observed something. When I installed just MySQL Server, there was no file with name my.cnf in the directory /etc/mysql. It was created only when I installed MySQL Workbench. Before it was installed, the socket mysql.sock was created in the directory /tmp. So, as a last trail, I deleted the file my.cnf from the directory /etc/mysql/ using the following commands, as a root user,

shell> cd /etc/mysql/

shell> rm my.cnf

Then I tried starting MySQL Service with this command,

shell> sudo /usr/local/mysql/support-files/mysql.server start

Surprisingly, MySQL Service got started and I could connected to it through command line. The socket was created in the directory /tmp. Then I found the location of pid file by issuing the following query in the mysql command prompt,

mysql> show variables where variable_name like '%pid%';

Now my MySQL Server is working fine when connected through command line and MySQL Workbench too. Now I can start or stop the server and can play with it! :)