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19.7. my.cnf
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19.7. my.cnf

19.7.1. bind-address

MySQL 通过 yum 安装后默认是监听 127.0.0.1 / ::1 如果你希望从其他IP访问3306端口，需要修改绑定地址为 0.0.0.0 

			
bind-address=127.0.0.1

0.0.0.0:3306

			
bind-address = 0.0.0.0

指定IP地址

			
[root@localhost ~]# ip addr show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: enp2s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:e0:70:81:9e:48 brd ff:ff:ff:ff:ff:ff
    inet 192.168.30.10/24 brd 192.168.30.255 scope global noprefixroute enp2s0
       valid_lft forever preferred_lft forever
    inet 192.168.30.11/24 brd 192.168.30.255 scope global secondary noprefixroute enp2s0
       valid_lft forever preferred_lft forever
    inet 192.168.30.12/24 brd 192.168.30.255 scope global secondary noprefixroute enp2s0
       valid_lft forever preferred_lft forever
    inet 192.168.30.13/24 brd 192.168.30.255 scope global secondary noprefixroute enp2s0
       valid_lft forever preferred_lft forever
    inet 192.168.30.14/24 brd 192.168.30.255 scope global secondary noprefixroute enp2s0
       valid_lft forever preferred_lft forever
    inet6 fe80::2e0:70ff:fe81:9e48/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: wlp1s0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 40:9f:38:b6:e0:55 brd ff:ff:ff:ff:ff:ff
4: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
    link/ether 02:42:f0:6f:b3:4b brd ff:ff:ff:ff:ff:ff
    inet 172.17.0.1/16 brd 172.17.255.255 scope global docker0
       valid_lft forever preferred_lft forever
45: br-a32fa1ca1437: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
    link/ether 02:42:d7:ae:ea:5d brd ff:ff:ff:ff:ff:ff
    inet 172.18.0.1/16 brd 172.18.255.255 scope global br-a32fa1ca1437
       valid_lft forever preferred_lft forever

上面服务器上配置多个IP地址

			
bind-address=192.168.30.10

19.7.2. 禁用TCP/IP链接

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

19.7.3. 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)

19.7.4. 最大链接数 max_connections


[mysqld]
max_connections=250

19.7.5. 默认引擎 storage-engine


[mysqld]
default-storage-engine=INNODB

19.7.6. max_allowed_packet


max_allowed_packet=8M

19.7.7. skip-name-resolve

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

19.7.8. timeout


[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。

19.7.9. 与复制有关的参数

19.7.9.1. 用于主库的选项 Master

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

19.7.9.2. 用于从库的选项 Slave 


replicate-do-db= 指定需要复制的数据库
replicate-ignore-db= 忽略复制的数据库

19.7.9.3. 逃过错误

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

19.7.10. 与 InnoDB 有关的配置项


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;

19.7.11. EVENT 设置

开启EVENT定时任务


event_scheduler=on

19.7.12. 日志

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

19.7.13. MySQL 5.7 my.cnf 实例

例 19.2. 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 19.3. 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

19.7.14. Example for my.cnf

例 19.4. 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

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19.6. MySQL Router 起始页 19.8. variables