Self correcting my.cnf for MySQL

createmycnf.sh

#!/bin/bash
(cat <<EOF
[mysqld]

## Performance Specific ##
##########################

innodb_buffer_pool_size 	= 12G		###	How much innodb data to store in memory. Higher = faster performance
innodb_file_per_table		= 1		###	Each innodb table is its own file on disk. 
innodb_flush_log_at_trx_commit 	= 2		### Flushes to disk in batches instead of per change
innodb_io_capacity		= 800		###	Min IO speed expected to write to disk. 
read_buffer_size 		= 2M		###	Helps with reading temp tables faster, bulk inserts and nested queries
read_rnd_buffer_size 		= 8M		###	Helps with multi range queries and ORDER Bys.
sort_buffer_size 		= 8M		### 	Helps with ORDER BY queries, which we have a lot of.
table_open_cache 		= 4096		###	Cache data about open tables. Saves reopening tables.
thread_cache_size 		= 256		### 	How many threads to cache. Can help reduce thread count.
thread_stack 			= 256k		###	How much cache each thread can have. Higher = more complicated results are cached
tmp_table_size 			= 64M		###	Max size a tmp table can be.
innodb_flush_method 		= O_DIRECT	##	Innodb flushes to table files directly
innodb_log_file_size 		= 512M		##	
innodb_log_files_in_group 	= 3		##
innodb_read_io_threads 		= 8		##	innodb background threads for reads. Helps with reads
join_buffer_size 		= 2M		##	Helps when a join doesn’t have an index or an index wont be more helpful than a full table scan
max_heap_table_size 		= 64M		##	Max size a tmp table can be in memory
query_cache_limit 		= 2M		##
query_cache_min_res_unit 	= 2048		##
query_cache_size 		= 196M		##
query_cache_type 		= 1		##	Caches complete query results. Data gets invalidated when underlying tables are changed.
table_open_cache_instances 	= 8		##	Divides the table cache to reduce contention
table-definition-cache 		= 4096		##	Stores table definitions - .frm files
key_buffer_size 		= 16M		#	As there are no MyISAM tables, this variable helps with MyISAM temp tables.
back_log			= 1500 		#	When MySQL gets a lot of connections in a short time, it will keep them in a back log
innodb_purge_threads		= 2		#	May reduce locks for when updates/deletes are run often 
innodb_sort_buffer_size		= 2M		#	Helps with index changes and create table statements
#innodb_page_cleaners 		= 4		#	Will help with start up and shutdown in 5.7
binlog_cache_size		= 128K		#	May speed up transactions
binlog_stmt_cache_size		= 1M		#	May speed up transactions

## General ##
#############

port=3306
default-storage-engine 		= InnoDB
innodb_file_format 		= Barracuda 		# The newer version of Innodb.
innodb_open_files 		= 131072		# Max number of open files innodb can have - Safety feature
interactive_timeout 		= 28800			
max_allowed_packet 		= 64M			# Current setting. Need to evaluate if can go down to 16M
max_connections 		= 780			# Maximum number of connections the server can have before not allowing anymore
#max_user_connections		
max-connect-errors 		= 1000000			
min_examined_row_limit 		= 1			# Slow log setting
open-files-limit 		= 65535			
sql_mode 			= NO_ENGINE_SUBSTITUTION			
sync_binlog 			= 0			# Moves to commiting in batches instead of per command
wait_timeout 			= 28800			


## Existing Replication Settings ##
###################################

EOF
) > my.cnf

mysql -e'show variables where variable_name like "server_id" or variable_name like "log_bin%" or variable_name like "relay_log%" or variable_name like "log_slave%" or variable_name like "%info%" or variable_name like "auto_increment%" or variable_name like "expire_logs_days" or variable_name like "binlog_format";' -NB | sed 's/\t/ = /g' | sed 's/ON/1/g' | sed 's/OFF/0/g' | grep -ve " = $" | egrep -v '(sync|recovery|space|purge)' | grep -v 'relay_log = ' | grep -v 'log_bin = ' | sed 's/_basename//g' >>my.cnf

(cat <<EOF


## UTF-8 compatibility ##
#########################

character-set-server			= utf8
init_connect					= 'SET collation_connection = utf8_general_ci'
character-set-server			= utf8
collation-server				= utf8_general_ci
init-connect					= 'SET NAMES utf8'

[client]
#loose-default-character-set		= utf8

[mysqld_safe]


EOF
) >> my.cnf
less my.cnf
echo 'Created my.cnf file in current directory'
echo "to use your new config file on this server, run:  cp my.cnf /etc/my.cnf"