While connecting to mysql showing socket error - mysql

Question

I have mysql server installed and it contains data also. I was trying to connect to mysql from ruby code. For that purpose I installed mysql gem using gem install mysql. The connection part in my program is giving below
require 'rubygems'
require 'mysql'
require 'csv'
$user_name = "root"
$pas_wrd = "password"
def mysql_connect(db_name)
begin
db = Mysql.real_connect("localhost", "#{$user_name}", "#{$pas_wrd}", "#{db_name}")
return db
rescue Mysql::Error => e
puts "Error code: #{e.errno}"
puts "Error message: #{e.error}"
puts "Error SQLSTATE: #{e.sqlstate}" if e.respond_to?("sqlstate")
end
end
It was written some day before and done the job. But when I try to use the same code It shows a mysql gem error,something like 'initialize' not found. By searching I found a solution like re-installing the gem. for re-installing I user the command rvmsudo gem install mysql. The above problem was solved. But it showing another error like
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)
I tried manually using mysql -u root -p
it is also showing the same error.
My mysql my.cnf content is given below.
[client]
port = 3306
socket = /var/run/mysqld/mysqld.sock
[mysqld_safe]
socket = /var/run/mysqld/mysqld.sock
nice = 0
[mysqld]
user = mysql
pid-file = /var/run/mysqld/mysqld.pid
socket = /var/run/mysqld/mysqld.sock
port = 3306
basedir = /usr
datadir = /var/lib/mysql
tmpdir = /tmp
lc-messages-dir = /usr/share/mysql
tmpdir = /home/presoft/Documents
skip-external-locking
The mysql is not running in my system.
ps aux | grep mysql
presoft 3823 0.0 0.0 4368 816 pts/0 S+ 10:41 0:00 grep --color=auto mysql
I tried to start using using sudo /etc/init.d/mysql start which gave the result of
Rather than invoking init scripts through /etc/init.d, use the service(8)
utility, e.g. service mysql start
Since the script you are attempting to invoke has been converted to an
Upstart job, you may also use the start(8) utility, e.g. start mysql
start: Job failed to start
Can any one help me to find a solution because db containing large amount of valuable data.
Thanks
Regards.

Answer 1

Use
service mysql start
This will start mysql service. newer linux machine consider mysql as service

Answer 2

I solved the problem from the above answer tip. The problem was my mysql server was corrupted.
So I first run the command
sudo apt-get purge mysql-common mysql-server
It will remove the all mysql files and configurations with out deleting the data. After running please carefully watch the process and do the need full any warning or error come.
I got a warning like
dpkg: warning: while removing mysql-common, directory '/etc/mysql' not empty so not removed.
So I removed the file and re run the above command. After the successful execution. I re-installed the mysql using
sudo apt-get install mysql-common mysql-server
then set the root password. After getting in to server The data is safe.