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1.4. my.cnf
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1.4. my.cnf

1.4.1. bind-address

MySQL 通過 yum 安裝後預設是監聽 127.0.0.1 / ::1 如果你希望從其他IP訪問3306連接埠，需要修改綁定地址為 0.0.0.0 

bind-address = 0.0.0.0

1.4.2. 禁用TCP/IP連結

與bind-address互斥，skip-networking 開啟，只能通過UNIX SOCKET連結，而不能使用IP地址連結

[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. 最大連結數 max_connections

[mysqld]
max_connections=250

1.4.5. 預設引擎 storage-engine

[mysqld]
default-storage-engine=INNODB

1.4.6. max_allowed_packet

max_allowed_packet=8M

1.4.7. skip-name-resolve

跳過域名解析

# vim /etc/mysql/my.cnf

[mysqld]
skip-name-resolve

MySQL 登錄緩慢，大量用戶排隊等待

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)

解決方案 my.cnf 配置檔案中加入skip-name-resolve

1.4.8. timeout

[mysqld]
wait_timeout=30
interactive_timeout=30

如果你沒有修改過MySQL的配置，預設情況下，wait_timeout的初始值是28800。

wait_timeout過大有弊端，其體現就是MySQL裡大量的SLEEP進程無法及時釋放，拖累系統性能，不過也不能把這個指設置的過小，否則你可能會遭遇到“MySQL has gone away”之類的問題，通常來說，我覺得把wait_timeout設置為10是個不錯的選擇，但某些情況下可能也會出問題，比如說有一個CRON腳本，其中兩次SQL查詢的間隔時間大於10秒的話，那麼這個設置就有問題了：

(1)interactive_timeout 參數含義：伺服器關閉互動式連接前等待活動的秒數。 參數預設值：28800秒（8小時）

(2)wait_timeout 參數含義：伺服器關閉非交互連接之前等待活動的秒數。

1.4.9. 與複製有關的參數

1.4.9.1. 用於主庫的選項 Master

定義 log-bin 檔案名

log-bin=mysql-bin

binlog 保留時間, 過期天數設置

expire-logs-days = 30
				

binlog-do-db=需要複製的資料庫名
binlog-ignore-db=不需要複製的資料庫

1.4.9.2. 用於從庫的選項 Slave 

replicate-do-db= 指定需要複製的資料庫
replicate-ignore-db= 忽略複製的資料庫

1.4.9.3. 逃過錯誤

主從複製經常遇到 Last_Errno: 1062 可以使用下面配置跳過

slave_skip_errors=1062

1.4.10. 與 InnoDB 有關的配置項

innodb_file_per_table

配置後重啟mysql運行下面命令將ibdata1拆分到tbl_name.ibd

OPTIMIZE TABLE tbl_name;

ls /var/lib/mysql/中查看 tbl_name.ibd檔案

臨時開啟

SET @@global.innodb_file_per_table = 1;

1.4.11. EVENT 設置

開啟EVENT定時任務

event_scheduler=on

1.4.12. 日誌

操作日誌

log = mysql.log

慢查詢日誌

log-slow-queries = slow.log
long_query_time = 5

錯誤日誌

[mysqld_safe]
log-error=/var/log/mysqld.log

1.4.13. MySQL 5.7 my.cnf 實例

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


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