与bind-address互斥，skip-networking 开启，只能通过UNIX SOCKET链接，而不能使用IP地址链接
[mysqld]
skip-networking
1.4.3. 配置字符集
Configuring Database Character Encoding
mysql> SHOW VARIABLES LIKE 'character_set_%';
+--------------------------+----------------------------+
| Variable_name | Value |
+--------------------------+----------------------------+
| character_set_client | latin1 |
| character_set_connection | latin1 |
| character_set_database | utf8 |
| character_set_filesystem | binary |
| character_set_results | latin1 |
| character_set_server | latin1 |
| character_set_system | utf8 |
| character_sets_dir | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+
8 rows in set (0.00 sec)
Server Character Set and Collation
shell> mysqld --character-set-server=latin1
shell> mysqld --character-set-server=latin1 \
--collation-server=latin1_swedish_ci
$ vim /etc/mysql/my.cnf
[mysqld]
character-set-server=utf8
collation_server=utf8_general_ci
init_connect='SET NAMES utf8'
[client]
character_set_client=utf8
mysql --default-character-set=utf8 -u root -p
mysql> show variables like 'character%';
+--------------------------+----------------------------+
| Variable_name | Value |
+--------------------------+----------------------------+
| character_set_client | utf8 |
| character_set_connection | utf8 |
| character_set_database | utf8 |
| character_set_filesystem | binary |
| character_set_results | utf8 |
| character_set_server | utf8 |
| character_set_system | utf8 |
| character_sets_dir | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+
8 rows in set (0.00 sec)
1.4.4. 最大链接数 max_connections
[mysqld]
max_connections=250
1.4.5. 默认引擎 storage-engine
[mysqld]
default-storage-engine=INNODB
1.4.6. max_allowed_packet
max_allowed_packet=8M
跳过域名解析
# vim /etc/mysql/my.cnf
[mysqld]
skip-name-resolve
MySQL 登录缓慢，大量用户排队等待
mysql> SHOW FULL PROCESSLIST;
+-----+----------------------+------------------------+------+---------+------+-------+-----------------------+
| Id | User | Host | db | Command | Time | State | Info |
+-----+----------------------+------------------------+------+---------+------+-------+-----------------------+
| 718 | unauthenticated user | 192.168.3.124:42075 | NULL | Connect | NULL | login | NULL |
| 719 | unauthenticated user | 192.168.3.124:42073 | NULL | Connect | NULL | login | NULL |
| 720 | unauthenticated user | 192.168.3.124:42074 | NULL | Connect | NULL | login | NULL |
| 721 | unauthenticated user | 192.168.3.124:42077 | NULL | Connect | NULL | login | NULL |
| 722 | unauthenticated user | 192.168.3.124:42076 | NULL | Connect | NULL | login | NULL |
| 723 | unauthenticated user | 192.168.3.124:42079 | NULL | Connect | NULL | login | NULL |
| 724 | unauthenticated user | 192.168.3.124:42078 | NULL | Connect | NULL | login | NULL |
| 725 | unauthenticated user | 192.168.3.124:42081 | NULL | Connect | NULL | login | NULL |
| 726 | unauthenticated user | 192.168.3.124:42080 | NULL | Connect | NULL | login | NULL |
| 727 | unauthenticated user | 192.168.3.124:42082 | NULL | Connect | NULL | login | NULL |
| 728 | unauthenticated user | 192.168.3.124:42083 | NULL | Connect | NULL | login | NULL |
| 729 | unauthenticated user | 192.168.3.124:42085 | NULL | Connect | NULL | login | NULL |
| 730 | unauthenticated user | 192.168.3.124:42084 | NULL | Connect | NULL | login | NULL |
| 731 | unauthenticated user | 192.168.3.124:42086 | NULL | Connect | NULL | login | NULL |
| 732 | unauthenticated user | 192.168.3.124:42087 | NULL | Connect | NULL | login | NULL |
| 733 | unauthenticated user | 192.168.3.124:42088 | NULL | Connect | NULL | login | NULL |
| 734 | unauthenticated user | 192.168.3.124:42089 | NULL | Connect | NULL | login | NULL |
| 735 | unauthenticated user | 192.168.3.124:42090 | NULL | Connect | NULL | login | NULL |
| 736 | unauthenticated user | 192.168.3.124:42091 | NULL | Connect | NULL | login | NULL |
| 737 | unauthenticated user | 192.168.3.124:42092 | NULL | Connect | NULL | login | NULL |
| 738 | unauthenticated user | 192.168.3.124:42093 | NULL | Connect | NULL | login | NULL |
| 739 | unauthenticated user | 192.168.3.124:42094 | NULL | Connect | NULL | login | NULL |
| 740 | unauthenticated user | 192.168.3.124:42095 | NULL | Connect | NULL | login | NULL |
| 741 | unauthenticated user | 192.168.3.124:42096 | NULL | Connect | NULL | login | NULL |
| 742 | unauthenticated user | 192.168.3.124:42097 | NULL | Connect | NULL | login | NULL |
| 743 | unauthenticated user | 192.168.3.124:42098 | NULL | Connect | NULL | login | NULL |
| 744 | unauthenticated user | 192.168.3.124:42099 | NULL | Connect | NULL | login | NULL |
| 745 | unauthenticated user | 192.168.3.124:42100 | NULL | Connect | NULL | login | NULL |
| 746 | unauthenticated user | 192.168.3.124:42101 | NULL | Connect | NULL | login | NULL |
| 747 | unauthenticated user | 192.168.3.124:42102 | NULL | Connect | NULL | login | NULL |
| 748 | unauthenticated user | 192.168.3.124:42103 | NULL | Connect | NULL | login | NULL |
| 749 | unauthenticated user | 192.168.3.124:42104 | NULL | Connect | NULL | login | NULL |
| 750 | unauthenticated user | 192.168.3.124:42068 | NULL | Connect | NULL | login | NULL |
| 751 | unauthenticated user | 192.168.3.124:42064 | NULL | Connect | NULL | login | NULL |
| 752 | unauthenticated user | 192.168.3.124:42071 | NULL | Connect | NULL | login | NULL |
| 753 | unauthenticated user | 192.168.3.124:42072 | NULL | Connect | NULL | login | NULL |
| 754 | unauthenticated user | 192.168.3.124:42067 | NULL | Connect | NULL | login | NULL |
| 755 | unauthenticated user | 192.168.3.124:42070 | NULL | Connect | NULL | login | NULL |
| 756 | unauthenticated user | 192.168.3.124:42069 | NULL | Connect | NULL | login | NULL |
| 757 | unauthenticated user | 192.168.3.124:42065 | NULL | Connect | NULL | login | NULL |
| 758 | unauthenticated user | 192.168.3.124:42112 | NULL | Connect | NULL | login | NULL |
| 759 | unauthenticated user | 192.168.3.50:4872 | NULL | Connect | NULL | login | NULL |
| 761 | unauthenticated user | 192.168.3.40:36363 | NULL | Connect | NULL | login | NULL |
| 762 | neo | www.example.com:56200 | NULL | Query | 0 | NULL | SHOW FULL PROCESSLIST |
+-----+----------------------+------------------------+------+---------+------+-------+-----------------------+
44 rows in set (0.00 sec)
mysql> SHOW FULL PROCESSLIST;
+-----+----------------------+------------------------+------+---------+------+-------+-----------------------+
| Id | User | Host | db | Command | Time | State | Info |
+-----+----------------------+------------------------+------+---------+------+-------+-----------------------+
| 718 | unauthenticated user | 192.168.3.124:42075 | NULL | Connect | NULL | login | NULL |
| 719 | unauthenticated user | 192.168.3.124:42073 | NULL | Connect | NULL | login | NULL |
| 720 | unauthenticated user | 192.168.3.124:42074 | NULL | Connect | NULL | login | NULL |
| 721 | unauthenticated user | 192.168.3.124:42077 | NULL | Connect | NULL | login | NULL |
| 722 | unauthenticated user | 192.168.3.124:42076 | NULL | Connect | NULL | login | NULL |
| 723 | unauthenticated user | 192.168.3.124:42079 | NULL | Connect | NULL | login | NULL |
| 724 | unauthenticated user | 192.168.3.124:42078 | NULL | Connect | NULL | login | NULL |
| 725 | unauthenticated user | 192.168.3.124:42081 | NULL | Connect | NULL | login | NULL |
| 726 | unauthenticated user | 192.168.3.124:42080 | NULL | Connect | NULL | login | NULL |
| 727 | unauthenticated user | 192.168.3.124:42082 | NULL | Connect | NULL | login | NULL |
| 728 | unauthenticated user | 192.168.3.124:42083 | NULL | Connect | NULL | login | NULL |
| 729 | unauthenticated user | 192.168.3.124:42085 | NULL | Connect | NULL | login | NULL |
| 730 | unauthenticated user | 192.168.3.124:42084 | NULL | Connect | NULL | login | NULL |
| 731 | unauthenticated user | 192.168.3.124:42086 | NULL | Connect | NULL | login | NULL |
| 732 | unauthenticated user | 192.168.3.124:42087 | NULL | Connect | NULL | login | NULL |
| 733 | unauthenticated user | 192.168.3.124:42088 | NULL | Connect | NULL | login | NULL |
| 734 | unauthenticated user | 192.168.3.124:42089 | NULL | Connect | NULL | login | NULL |
| 735 | unauthenticated user | 192.168.3.124:42090 | NULL | Connect | NULL | login | NULL |
| 736 | unauthenticated user | 192.168.3.124:42091 | NULL | Connect | NULL | login | NULL |
| 737 | unauthenticated user | 192.168.3.124:42092 | NULL | Connect | NULL | login | NULL |
| 738 | unauthenticated user | 192.168.3.124:42093 | NULL | Connect | NULL | login | NULL |
| 739 | unauthenticated user | 192.168.3.124:42094 | NULL | Connect | NULL | login | NULL |
| 740 | unauthenticated user | 192.168.3.124:42095 | NULL | Connect | NULL | login | NULL |
| 741 | unauthenticated user | 192.168.3.124:42096 | NULL | Connect | NULL | login | NULL |
| 742 | unauthenticated user | 192.168.3.124:42097 | NULL | Connect | NULL | login | NULL |
| 743 | unauthenticated user | 192.168.3.124:42098 | NULL | Connect | NULL | login | NULL |
| 744 | unauthenticated user | 192.168.3.124:42099 | NULL | Connect | NULL | login | NULL |
| 745 | unauthenticated user | 192.168.3.124:42100 | NULL | Connect | NULL | login | NULL |
| 746 | unauthenticated user | 192.168.3.124:42101 | NULL | Connect | NULL | login | NULL |
| 747 | unauthenticated user | 192.168.3.124:42102 | NULL | Connect | NULL | login | NULL |
| 748 | unauthenticated user | 192.168.3.124:42103 | NULL | Connect | NULL | login | NULL |
| 749 | unauthenticated user | 192.168.3.124:42104 | NULL | Connect | NULL | login | NULL |
| 750 | unauthenticated user | 192.168.3.124:42068 | NULL | Connect | NULL | login | NULL |
| 751 | unauthenticated user | 192.168.3.124:42064 | NULL | Connect | NULL | login | NULL |
| 752 | unauthenticated user | 192.168.3.124:42071 | NULL | Connect | NULL | login | NULL |
| 753 | unauthenticated user | 192.168.3.124:42072 | NULL | Connect | NULL | login | NULL |
| 754 | unauthenticated user | 192.168.3.124:42067 | NULL | Connect | NULL | login | NULL |
| 755 | unauthenticated user | 192.168.3.124:42070 | NULL | Connect | NULL | login | NULL |
| 756 | unauthenticated user | 192.168.3.124:42069 | NULL | Connect | NULL | login | NULL |
| 757 | unauthenticated user | 192.168.3.124:42065 | NULL | Connect | NULL | login | NULL |
| 758 | unauthenticated user | 192.168.3.124:42112 | NULL | Connect | NULL | login | NULL |
| 759 | unauthenticated user | 192.168.3.50:4872 | NULL | Connect | NULL | login | NULL |
| 761 | unauthenticated user | 192.168.3.40:36363 | NULL | Connect | NULL | login | NULL |
| 762 | neo | www.example.com:56200 | NULL | Query | 0 | NULL | SHOW FULL PROCESSLIST |
+-----+----------------------+------------------------+------+---------+------+-------+-----------------------+
44 rows in set (0.00 sec)
解决方案 my.cnf 配置文件中加入skip-name-resolve
[mysqld]
wait_timeout=30
interactive_timeout=30
如果你没有修改过MySQL的配置，缺省情况下，wait_timeout的初始值是28800。
wait_timeout过大有弊端，其体现就是MySQL里大量的SLEEP进程无法及时释放，拖累系统性能，不过也不能把这个指设置的过小，否则你可能会遭遇到“MySQL has gone away”之类的问题，通常来说，我觉得把wait_timeout设置为10是个不错的选择，但某些情况下可能也会出问题，比如说有一个CRON脚本，其中两次SQL查询的间隔时间大于10秒的话，那么这个设置就有问题了：
(1)interactive_timeout 参数含义：服务器关闭交互式连接前等待活动的秒数。 参数默认值：28800秒（8小时）
(2)wait_timeout 参数含义：服务器关闭非交互连接之前等待活动的秒数。
定义 log-bin 文件名
log-bin=mysql-bin
binlog 保留时间, 过期天数设置
expire-logs-days = 30
binlog-do-db=需要复制的数据库名
binlog-ignore-db=不需要复制的数据库
replicate-do-db= 指定需要复制的数据库
replicate-ignore-db= 忽略复制的数据库
主从复制经常遇到 Last_Errno: 1062 可以使用下面配置跳过
slave_skip_errors=1062
innodb_file_per_table
配置后重启mysql运行下面命令将ibdata1拆分到tbl_name.ibd
OPTIMIZE TABLE tbl_name;
ls /var/lib/mysql/中查看 tbl_name.ibd文件
临时开启
SET @@global.innodb_file_per_table = 1;
开启EVENT定时任务
event_scheduler=on
操作日志
log = mysql.log
慢查询日志
log-slow-queries = slow.log
long_query_time = 5
错误日志
[mysqld_safe]
log-error=/var/log/mysqld.log
1.4.13. MySQL 5.7 my.cnf 实例
例 1.1. my.cnf
[root@netkiller ~]# cat /etc/my.cnf
# For advice on how to change settings please see
# http://dev.mysql.com/doc/refman/5.7/en/server-configuration-defaults.html
[mysqld]
#
# Remove leading # and set to the amount of RAM for the most important data
# cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.
# innodb_buffer_pool_size = 128M
#
# Remove leading # to turn on a very important data integrity option: logging
# changes to the binary log between backups.
# log_bin
#
# Remove leading # to set options mainly useful for reporting servers.
# The server defaults are faster for transactions and fast SELECTs.
# Adjust sizes as needed, experiment to find the optimal values.
# join_buffer_size = 128M
# sort_buffer_size = 2M
# read_rnd_buffer_size = 2M
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
!includedir /etc/my.cnf.d
例 1.2. my.cnf
[root@netkiller ~]# cat /etc/my.cnf.d/default.cnf
[mysqld]
skip-name-resolve
max_connections=4096
default-storage-engine=INNODB
#wait_timeout=300
#interactive_timeout=300
character-set-server=utf8
collation_server=utf8_general_ci
init_connect='SET NAMES utf8'
explicit_defaults_for_timestamp=true
query_cache_type=1
query_cache_size=512M
table-open-cache=2000
#validate-password=OFF
sql_mode = STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
[client]
default-character-set=utf8
#character_set_client=utf8
1.4.14. Example for my.cnf
例 1.3. my.cnf
# Example MySQL config file for very large systems.
#
# This is for a large system with memory of 1G-2G where the system runs mainly
# MySQL.
#
# In this file, you can use all long options that a program supports.
# If you want to know which options a program supports, run the program
# with the "--help" option.
# The following options will be passed to all MySQL clients
[client]
#password = your_password
port = 3306
socket = /var/lib/mysql/mysql.sock
# Here follows entries for some specific programs
character-set-server=utf8
# The MySQL server
[mysqld]
port = 3306
socket = /var/lib/mysql/mysql.sock
skip-external-locking
key_buffer_size = 384M
max_allowed_packet = 1M
table_open_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
# Try number of CPU's*2 for thread_concurrency
thread_concurrency = 8
#skip-networking
# Replication Master Server (default)
# binary logging is required for replication
log-bin=mysql-bin
# required unique id between 1 and 2^32 - 1
# defaults to 1 if master-host is not set
# but will not function as a master if omitted
server-id = 1
# Replication Slave (comment out master section to use this)
#
#
# required unique id between 2 and 2^32 - 1
# (and different from the master)
# defaults to 2 if master-host is set
# but will not function as a slave if omitted
#server-id = 2
#
# The replication master for this slave - required
#master-host = <hostname>
#
# The username the slave will use for authentication when connecting
# to the master - required
#master-user = <username>
#
# The password the slave will authenticate with when connecting to
# the master - required
#master-password = <password>
#
# The port the master is listening on.
# optional - defaults to 3306
#master-port = <port>
#
# binary logging - not required for slaves, but recommended
#log-bin=mysql-bin
#
# binary logging format - mixed recommended
#binlog_format=mixed
# Uncomment the following if you are using InnoDB tables
#innodb_data_home_dir = /var/lib/mysql
#innodb_data_file_path = ibdata1:2000M;ibdata2:10M:autoextend
#innodb_log_group_home_dir = /var/lib/mysql
# You can set .._buffer_pool_size up to 50 - 80 %
# of RAM but beware of setting memory usage too high
#innodb_buffer_pool_size = 384M
#innodb_additional_mem_pool_size = 20M
# Set .._log_file_size to 25 % of buffer pool size
#innodb_log_file_size = 100M
#innodb_log_buffer_size = 8M
#innodb_flush_log_at_trx_commit = 1
#innodb_lock_wait_timeout = 50
# Here follows entries for some specific programs
skip-name-resolve
default-storage-engine = INNODB
character-set-server=utf8
collation_server=utf8_general_ci
init_connect='SET NAMES utf8'
max_connections = 4096
max_connect_errors = 10
pid-file = mysql.pid
log = mysql.log
log-error = mysql_error.log
log-slow-queries = slow.log
long_query_time = 10
[mysqldump]
quick
max_allowed_packet = 16M
[mysql]
no-auto-rehash
# Remove the next comment character if you are not familiar with SQL
#safe-updates
[myisamchk]
key_buffer_size = 256M
sort_buffer_size = 256M
read_buffer = 2M
write_buffer = 2M
[mysqlhotcopy]
interactive-timeout
原文出处：Netkiller 系列 手札
本文作者：陈景峯
转载请与作者联系，同时请务必标明文章原始出处和作者信息及本声明。
值得收藏！my.cnf配置文档详解
