How to harden mysql server

Hardening mysql

First all, before doing anything take the backup of configuration file.
cp /etc/my.cnf{,.orig}
vi /etc/my.cnf

[mysqld]
skip-locking
key_buffer = 384M
max_allowed_packet = 1M
max_connections = 500
max_user_connections = 35
wait_timeout=40
connect_timeout=10
table_cache = 512
sort_buffer_size = 2M
read_buffer_size = 2M
read_rnd_buffer_size = 8M
myisam_sort_buffer_size = 64M
thread_cache_size = 8
query_cache_size = 32M
thread_concurrency = 8
server-id = 1

[mysqldump]
quick
max_allowed_packet = 16M
[mysql]
no-auto-rehash

[myisamchk]
key_buffer = 256M
sort_buffer_size = 256M
read_buffer = 2M
write_buffer = 2M

[mysqlhotcopy]
interactive-timeout

Save the file.

killall -9 mysqld safe_mysqld mysqld_safe 2>/dev/null
pkill -9 mysql
pkill -9 mysqld

Restart mysql service.
/etc/init.d/mysql restart