Recommended MySQL my.cnf Settings

MySQL

I did my research on google read some blogs but I found nothing that really works in my case.
After my, mysql crashed several times testing configurations, I have no option than ask for some help here.

Can somebody give me some hints about what values are recommended in my.cnf for a heavy duty database server (12 tables, more than 50G of data) with the following specifications:
`

root@blah:/etc/mysql# lscpu 
Architecture:          x86_64
CPU op-mode(s):        32-bit, 64-bit
Byte Order:            Little Endian
CPU(s):                16
On-line CPU(s) list:   0-15
Thread(s) per core:    16
Core(s) per socket:    1
Socket(s):             1
NUMA node(s):          1
Vendor ID:             GenuineIntel
CPU family:            6
Model:                 62
Stepping:              4
CPU MHz:               2600.092
BogoMIPS:              5200.18
Hypervisor vendor:     Xen
Virtualization type:   full
L1d cache:             32K
L1i cache:             32K
L2 cache:              256K
L3 cache:              20480K
NUMA node0 CPU(s):     0-15
root@blah:/etc/mysql# free -m
             total       used       free     shared    buffers     cached
Mem:         64237       2747      61490         19        189       1811
-/+ buffers/cache:        746      63491
Swap: 

    2047          0       2047

This server is used only as database so I don't have to worry about anything else. Just to make sure that MySql is getting all the juice and use all resources in the best possible way.

my.cnf file I have is looking like this:

root@blah:/etc/mysql# cat my.cnf
#
# The MySQL database server configuration file.
#
# You can copy this to one of:
# - "/etc/mysql/my.cnf" to set global options,
# - "~/.my.cnf" to set user-specific options.
# 
# One can use all long options that the program supports.
# Run program with --help to get a list of available options and with
# --print-defaults to see which it would actually understand and use.
#
# For explanations see
# http://dev.mysql.com/doc/mysql/en/server-system-variables.html

# This will be passed to all mysql clients
# It has been reported that passwords should be enclosed with ticks/quotes
# escpecially if they contain "#" chars...
# Remember to edit /etc/mysql/debian.cnf when changing the socket location.
[client]
port        = 3306
socket      = /var/run/mysqld/mysqld.sock

# Here is entries for some specific programs
# The following values assume you have at least 32M ram

# This was formally known as [safe_mysqld]. Both versions are currently parsed.
[mysqld_safe]
socket      = /var/run/mysqld/mysqld.sock
nice        = 0

[mysqld]
#
# * Basic Settings
#
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
#skip-external-locking
#
# Instead of skip-networking the default is now to listen only on
# localhost which is more compatible and is not less secure.
#bind-address       = 127.0.0.1
#
# * Fine Tuning
#
key_buffer      = 16M
max_allowed_packet  = 16M
thread_stack        = 192K
thread_cache_size       = 8
# This replaces the startup script and checks MyISAM tables if needed
# the first time they are touched
myisam-recover         = BACKUP
#max_connections        = 100
#table_cache            = 64
#thread_concurrency     = 10
#
# * Query Cache Configuration
#
query_cache_limit   = 1M
query_cache_size        = 16M
#
# * Logging and Replication
#
# Both location gets rotated by the cronjob.
# Be aware that this log type is a performance killer.
# As of 5.1 you can enable the log at runtime!
#general_log_file        = /var/log/mysql/mysql.log
#general_log             = 1
#
# Error log - should be very few entries.
#
log_error = /var/log/mysql/error.log
#
# Here you can see queries with especially long duration
#log_slow_queries   = /var/log/mysql/mysql-slow.log
#long_query_time = 2
#log-queries-not-using-indexes
#
# The following can be used as easy to replay backup logs or for replication.
# note: if you are setting up a replication slave, see README.Debian about
#       other settings you may need to change.
#server-id      = 1
#log_bin            = /var/log/mysql/mysql-bin.log
expire_logs_days    = 10
max_binlog_size         = 100M
#binlog_do_db       = include_database_name
#binlog_ignore_db   = include_database_name
#
# * InnoDB
#
# InnoDB is enabled by default with a 10MB datafile in /var/lib/mysql/.
# Read the manual for more InnoDB related options. There are many!
#
# * Security Features
#
# Read the manual, too, if you want chroot!
# chroot = /var/lib/mysql/
#
# For generating SSL certificates I recommend the OpenSSL GUI "tinyca".
#
# ssl-ca=/etc/mysql/cacert.pem
# ssl-cert=/etc/mysql/server-cert.pem
# ssl-key=/etc/mysql/server-key.pem



[mysqldump]
quick
quote-names
max_allowed_packet  = 16M

[mysql]
#no-auto-rehash # faster start of mysql but no tab completition

[isamchk]
key_buffer      = 16M

#
# * IMPORTANT: Additional settings that can override those from this file!
#   The files must end with '.cnf', otherwise they'll be ignored.
#
!includedir /etc/mysql/conf.d/

Best Answer

I see you have 64GB RAM, and its all for MySQL server, which is nice. First I would suggest increasing your cache sizes, tmp_tables, etc, you can search those on Google. If you are using InnoDB tables, I suggest you tweak those too. Below I will give some suggestions, but ultimately its up to you what to do, and the best you can do is read up and test out different configs.

To check config params, use this query, modify like part or omit it at all, this way you know for sure if your settings are there:

show variables like '%log%';

Skip name resolve, this will make mysql faster as it doesn't need to resolve DNS, be sure that you use IP addresses when connecting to you server afterwords:

[mysqld]
skip-name-resolve

Recommended giving 64M for both values for every 1 GB of RAM on the server. This boosts performance, change these values to your needs

tmp_table_size= 2000M
max_heap_table_size= 2000M
max_tmp_tables=300

Log slow queries, long_query_time is number of seconds for query to be long, adjust accordingly

[mysqld]
slow-query-log = 1
slow-query-log-file = /var/log/mysql-slow.log
long_query_time = 1

Some settings that you need to tweak I give below.

sort_buffer_size=10M 
read_buffer_size=10M 
table_open_cache=8000
query_cache_limit=50M
join_buffer=10M

These are generally the main settings you need to tweak, numbers here are for your reference only, you should change/tweak them accordingly. Read Mysql docs for meaning of the each of those.

IF you are running phpMyAdmin, there will be Database Status, go there and it will show you red flags. Other than that you can manually check up on some parameters like this: SHOW GLOBAL STATUS LIKE 'Opened_tables';

Once in a while check if you have fragmented tables or if they need repair. This command solves it:

mysqlcheck -u root --auto-repair --optimize --all-databases

Another userful tool is mysqltuner, install and run it too.

Hope this helps.

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