Mysql configuration

my.cnf

#
# These groups are read by MariaDB server.
# Use it for options that only the server (but not clients) should see
#
# See the examples of server my.cnf files in /usr/share/mysql/
#

# this is read by the standalone daemon and embedded servers
[server]

# this is only for the mysqld standalone daemon
[mysqld]

# this is only for embedded server
[embedded]

# This group is only read by MariaDB-5.5 servers.
# If you use the same .cnf file for MariaDB of different versions,
# use this group for options that older servers don't understand
[mysqld-5.5]

# These two groups are only read by MariaDB servers, not by MySQL.
# If you use the same .cnf file for MySQL and MariaDB,
# you can put MariaDB-only options here
[mariadb]

[mariadb-5.5]

# GENERAL #
server-id                      = 2
user                           = mysql
default-storage-engine         = InnoDB
#socket                        = /var/data/mysql.sock
pid-file                       = /var/data/mysql.pid

# MyISAM #
key-buffer-size                = 32M
myisam-recover                 = FORCE,BACKUP

# SAFETY #
max-allowed-packet             = 512M
max-connect-errors             = 1000000

# DATA STORAGE #
datadir                        = /var/data/db


# BINARY LOGGING #
log-bin                        = /var/data/db/mysql-bin
binlog_format                  = MIXED
expire-logs-days               = 14
sync-binlog                    = 1
binlog-cache-size              = 64M

# CACHES AND LIMITS #
tmp-table-size                 = 32M
max-heap-table-size            = 32M
query-cache-type               = 1
query-cache-size               = 128M
query-cache-limit              = 
max-connections                = 500
thread-cache-size              = 128
#open_files_limit               = 65535
table-definition-cache         = 4096
table-open-cache               = 4096
tmpdir                         = /var/data/tmpfs/

# INNODB #
innodb-flush-method            = O_DIRECT
innodb-log-buffer-size         = 256M
innodb-log-files-in-group      = 2
innodb-log-file-size           = 256M
innodb-flush-log-at-trx-commit = 1
innodb-file-per-table          = 1
innodb-buffer-pool-size        = 20G
innodb_data_file_path          =  ibdata1:100G:autoextend:max:400G
innodb_buffer_pool_instances   = 12 
join-buffer-size               = 256M
transaction-isolation          = READ-COMMITTED

# LOGGING #
log-error                      = /var/data/mysql-error.log
log-queries-not-using-indexes  = 1
slow-query-log                 = 1
slow-query-log-file            = /var/data/mysql-slow.log


[mysqld_safe] 
open_files_limit               = 65535