17.1 MySQL主从介绍
MySQL主从又叫做Replication、AB复制。简单讲就是A和B两台机器做主从后，在A上写数据，另外一台B也会跟着写数据，两者数据实时同步的
MySQL主从是基于binlog的，主上须开启binlog才能进行主从。bilog，是二进制文件，无法cat
主从过程大致有3个步骤
1）主将更改操作记录到binlog里
2）从将主的binlog事件(sql语句)同步到从本机上并记录在relaylog里
3）从根据relaylog里面的sql语句按顺序执行
主上有一个log dump线程，用来和从的I/O线程传递binlog
从上有两个线程，其中I/O线程用来同步主的binlog并生成relaylog，另外一个SQL线程用来把relaylog里面的sql语句落地
mysql主从原理图
使用场景：
一、数据备份，主机器宕机，从机器还能随时对web提供服务
二、数据备份且可以分担主机器被调用数据时的压力，mysql主从，是有方向性的，写数据，必须从主机器开始；如果不依照原理会导致数据紊乱
17.2 准备工作
主从配置，主上操作
mysql安装总结
进入src专用的下载目录下，下载mysql二进制免编译包
wget mysql5.6，x64位
wget http://mirrors.sohu.com/mysql/MySQL-5.6/mysql-5.6.36-linux-glibc2.5-x86_64.tar.gz解压
tar zxvf mysql-5.6.36-linux-glibc2.5-x86_64.tar.gz移动
mv mysql-5.6.36-linux-glibc2.5-x86_64 /usr/local/mysql移动时，需注意这个目录是否已经存在，如果存在了，需要删除旧文件
初始化配置
进入所在的mysql目录
[root@test221 mysql]# pwd
/usr/local/mysql
./scripts/mysql_install_db --user=mysql --datadir=/data/mysql
--user=mysql 需提前创建
编辑my.cnf文件（7版本的centos系统，就自带安装一个mariadb，所以就会自动生成有一个my.cnf，就省去了拷贝）
主221
vim /etc/my.cnf //添加以下内容
server_id = 221
log_bin = test221
datadir=/data/mysql
socket=/tmp/mysql.sock
从222和主一样安装mysql5.6，也可以直接同步主的/usr/local/mysql:
vim /etc/my.cnf //添加以下内容
server_id = 222拷贝启动脚本
cp support-files/mysql.server /etc/init.d/mysqld 编辑启动脚本
vim /etc/init.d/mysqld //对以下两行进行指定路径
basedir=
datadir=指定basedir的路径 /usr/local/mysql
指定datadir的路径 /data/mysql
最重要的一步，记得查看/data/mysql 的默认属主、属组，如果不是mysql的，启东时会因为无法写入数据而不能启动
chomd mysql:mysql /data/mysql然后就可以尝试启动
/etc/init.d/mysql start主机器
172.16.22.221
mysql启动情况
[root@test221 ~]# ps aux |grep mysql
root 1061 0.0 0.1 115392 1688 ? S 17:14 0:00 /bin/sh /usr/local/mysql/bin/mysqld_safe --datadir=/data/mysql --pid-file=/data/mysql/test221.pid
mysql 1511 1.3 45.3 1300816 452976 ? Sl 17:14 0:02 /usr/local/mysql/bin/mysqld --basedir=/usr/local/mysql --datadir=/data/mysql --plugin-dir=/usr/local/mysql/lib/plugin --user=mysql --log-error=/data/mysql/test221.err --pid-file=/data/mysql/test221.pid --socket=/tmp/mysql.sock
root 2136 0.0 0.0 112684 980 pts/0 S+ 17:17 0:00 grep --color=auto mysql
[root@test221 ~]#
从机器
172.16.22.222
mysql启动情况
[root@test222 ~]# ps aux |grep mysql
root 1288 0.0 0.1 115392 1680 ? S 17:15 0:00 /bin/sh /usr/local/mysql/bin/mysqld_safe --datadir=/data/mysql --pid-file=/data/mysql/test222.pid
mysql 1729 1.7 45.2 1300784 452076 ? Sl 17:15 0:02 /usr/local/mysql/bin/mysqld --basedir=/usr/local/mysql --datadir=/data/mysql --plugin-dir=/usr/local/mysql/lib/plugin --user=mysql --log-error=/data/mysql/test222.err --pid-file=/data/mysql/test222.pid --socket=/tmp/mysql.sock
root 2183 0.0 0.0 112680 980 pts/0 S+ 17:17 0:00 grep --color=auto mysql
[root@test222 ~]#
17.3 配置主
安装mysql
修改my.cnf，增加server-id=221和log_bin=test221
修改完配置文件后，启动或者重启mysqld服务
把mysql库备份并恢复成testing库，作为测试数据
mysqldump -uroot mysql > /tmp/mysql.sql
mysql -uroot -e “create database testing”
mysql -uroot testing < /tmp/mysql.sql
创建用作同步数据的用户
grant replication slave on . to 'repl'@slave_ip identified by 'password';
flush tables with read lock;
show master status;
修改主机器上的配置文件
[root@test221 ~]# vi /etc/my.cnf
[mysqld]
datadir=/data/mysql
socket=/tmp/mysql.sock
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
# Settings user and group are ignored when systemd is used.
# If you need to run mysqld under a different user or group,
# customize your systemd unit file for mariadb according to the
# instructions in http://fedoraproject.org/wiki/Systemd
[mysqld_safe]
#log-error=/var/log/mariadb/mariadb.log
#pid-file=/var/run/mariadb/mariadb.pid
#
# include all files from the config directory
#
#!includedir /etc/my.cnf.d
~
~
~
~
~
~
~
~
"/etc/my.cnf" 19L, 560C更改为
[root@test221 ~]# vi /etc/my.cnf
[mysqld]
datadir=/data/mysql
socket=/tmp/mysql.sock
server-id=221
log_bin=test221
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
# Settings user and group are ignored when systemd is used.
# If you need to run mysqld under a different user or group,
# customize your systemd unit file for mariadb according to the
# instructions in http://fedoraproject.org/wiki/Systemd
[mysqld_safe]
#log-error=/var/log/mariadb/mariadb.log
#pid-file=/var/run/mariadb/mariadb.pid
#
# include all files from the config directory
#
#!includedir /etc/my.cnf.d
~
~
~
~
~
~
:wq修改之后要重启mysql,进入/data/mysql/目录下
[root@test221 ~]# /etc/init.d/mysqld restart
Shutting down MySQL.. SUCCESS!
Starting MySQL.. SUCCESS!
[root@test221 ~]#
[root@test221 ~]# pwd
/root
[root@test221 ~]# cd /data/mysql
[root@test221 mysql]# ls -lt
总用量 110768
-rw-rw----. 1 mysql mysql 50331648 1月 12 19:44 ib_logfile0
-rw-rw----. 1 mysql mysql 12582912 1月 12 19:44 ibdata1
-rw-rw----. 1 mysql mysql 29700 1月 12 19:43 test221.err
-rw-rw----. 1 mysql mysql 5 1月 12 19:43 test221.pid
-rw-rw----. 1 mysql mysql 21 1月 12 19:43 test221.index
-rw-rw----. 1 mysql mysql 120 1月 12 19:43 test221.000001
drwx------. 2 mysql mysql 4096 1月 11 20::12 zrlog
-rw-rw----. 1 mysql mysql 44847 12月 31 22:02 localhost.err
drwx------. 2 mysql mysql 4096 12月 30 23:13 mysql2
-rw-rw----. 1 mysql mysql 49405 12月 24 23:57 localhost.localdomain.err
-rw-rw----. 1 mysql mysql 56 12月 14 20:44 auto.cnf
drwx------. 2 mysql mysql 4096 12月 14 20:31 mysql
drwx------. 2 mysql mysql 4096 12月 14 20:31 performance_schema
-rw-rw----. 1 mysql mysql 50331648 12月 14 20:31 ib_logfile1
drwx------. 2 mysql mysql 6 12月 14 20:31 test
[root@test221 mysql]#
.index 索引页，这个文件是必须要有的
.000001 这个是二进制日志文件，会持续生成2、3、4等等（这个文件是实现主从配置的根本，没有这个文件根本没有办法实现）
第二步，准备一个数据，做演示用的，重新来搞一个数据出来，在blog基础上备份一个出来
[root@test221 mysql]# ls -lt
总用量 110768
-rw-rw----. 1 mysql mysql 50331648 1月 12 19:44 ib_logfile0
-rw-rw----. 1 mysql mysql 12582912 1月 12 19:44 ibdata1
-rw-rw----. 1 mysql mysql 29700 1月 12 19:43 test221.err
-rw-rw----. 1 mysql mysql 5 1月 12 19:43 test221.pid
-rw-rw----. 1 mysql mysql 21 1月 12 19:43 test221.index
-rw-rw----. 1 mysql mysql 120 1月 12 19:43 test221.000001
drwx------. 2 mysql mysql 4096 1月 11 20::12 zrlog
-rw-rw----. 1 mysql mysql 44847 12月 31 22:02 localhost.err
drwx------. 2 mysql mysql 4096 12月 30 23:13 mysql2
-rw-rw----. 1 mysql mysql 49405 12月 24 23:57 localhost.localdomain.err
-rw-rw----. 1 mysql mysql 56 12月 14 20:44 auto.cnf
drwx------. 2 mysql mysql 4096 12月 14 20:31 mysql
drwx------. 2 mysql mysql 4096 12月 14 20:31 performance_schema
-rw-rw----. 1 mysql mysql 50331648 12月 14 20:31 ib_logfile1
drwx------. 2 mysql mysql 6 12月 14 20:31 test
[root@test221 mysql]# mysqldump -uroot -paiker123456 zrlog > /tmp/zrlog.sql
Warning: Using a password on the command line interface can be insecure.
[root@test221 mysql]#
[root@test221 mysql]# du -sh /tmp/zrlog.sql
12K /tmp/zrlog.sql
[root@test221 mysql]# 新创建一个库,叫testing的库
[root@test221 mysql]# mysql -uroot -paiker123456 -e "create database testing"
Warning: Using a password on the command line interface can be insecure.
[root@test221 mysql]# 创建库之后还需要把这个数据恢复一下
[root@test221 mysql]# mysql -uroot -paiker123456 testing < /tmp/zrlog.sql
Warning: Using a password on the command line interface can be insecure.
[root@test221 mysql]# 现在要做的主从，参考的对象就是这个库 testing这个库
[root@test221 mysql]# ls -lt
总用量 225468
-rw-rw----. 1 mysql mysql 50331648 1月 12 19:56 ib_logfile0
-rw-rw----. 1 mysql mysql 79691776 1月 12 19:56 ibdata1
-rw-rw----. 1 mysql mysql 10543 1月 12 19:56 test221.000001
drwx------. 2 mysql mysql 4096 1月 12 19:56 testing
-rw-rw----. 1 mysql mysql 29700 1月 12 19:43 test221.err
-rw-rw----. 1 mysql mysql 5 1月 12 19:43 test221.pid
-rw-rw----. 1 mysql mysql 21 1月 12 19:43 test221.index
drwx------. 2 mysql mysql 4096 1月 11 20:12 zrlog
-rw-rw----. 1 mysql mysql 44847 12月 31 22:02 localhost.err
drwx------. 2 mysql mysql 4096 12月 30 23:13 mysql2
-rw-rw----. 1 mysql mysql 49405 12月 24 23:57 localhost.localdomain.err
-rw-rw----. 1 mysql mysql 56 12月 14 20:44 auto.cnf
drwx------. 2 mysql mysql 4096 12月 14 20:31 mysql
drwx------. 2 mysql mysql 4096 12月 14 20:31 performance_schema
-rw-rw----. 1 mysql mysql 50331648 12月 14 20:31 ib_logfile1
drwx------. 2 mysql mysql 6 12月 14 20:31 test
[root@test221 mysql]#
先进入到mysql里面来
[root@test221 mysql]# mysql -uroot -paiker123456
Warning: Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 6
Server version: 5.6.36-log MySQL Community Server (GPL)
Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql>
创建用作同步数据的用户
mysql> grant replication slave on *.* to 'repl'@'172.16.22.222' identified by 'test22111';
Query OK, 0 rows affected (0.00 sec)
mysql> 不要忘记给它锁上，目的是不要再让它继续写了
锁表的目的是不让表继续写，因为一会需要做从机器配置，需要进行一个同步，让两台机器同步，保证两台机器的数据一致，同步才不会出错
mysql> flush tables with read lock;
Query OK, 0 rows affected (0.00 sec)
mysql> 做一个show master status；
mysql> show master status;
+--------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+--------------------+----------+--------------+------------------+-------------------+
| test221.000001 | 10755 | | | |
+--------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
mysql>
mysql> quit
Bye
[root@test221 mysql]#
需要记住binlog的filename，记住file 的位置，一会儿要用到它
一会儿要去从机器 上 同步这些库 （高亮的为库）
[root@test221 mysql]# ls
testing test221.index ib_logfile1 mysql2 zrlog
test221.err auto.cnf localhost.err performance_schema
test221.pid ibdata1 localhost.localdomain.err test
test221.000001 ib_logfile0 mysql
[root@test221 mysql]# ls /tmp/zrlog.sql
/tmp/zrlog.sql
[root@test221 mysql]#
把这下面的库都做一个备份
[root@test221 mysql]# mysqldump -uroot -paiker123456 mysql2 > /tmp/my2.sql
Warning: Using a password on the command line interface can be insecure.
[root@test221 mysql]# ls /tmp/*sql
/tmp/blog,sql /tmp/blog.sql /tmp/my2.sql /tmp/zrlog.sql
[root@test221 mysql]# 17.4 配置从
安装mysql，已经做了
查看my.cnf，配置server-id=222，要求和主不一样
修改完配置文件后，启动或者重启mysqld服务
把主上testing库同步到从上
可以先创建testing库，然后把主上的/tmp/mysql.sql拷贝到从上，然后导入testing库
mysql -uroot
stop slave；
change master to master_host='', master_user='repl', master_password='', master_log_file='', master_log_pos=xx,
start slave;
还要到主上执行 unlock tables
进入/etc/my.cnf
[root@test222 ~]# vi /etc/my.cnf
[mysqld]
datadir=/data/mysql
socket=/tmp/mysql.sock
server-id=222
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
# Settings user and group are ignored when systemd is used.
# If you need to run mysqld under a different user or group,
# customize your systemd unit file for mariadb according to the
# instructions in http://fedoraproject.org/wiki/Systemd
[mysqld_safe]
#log-error=/var/log/mariadb/mariadb.log
#pid-file=/var/run/mariadb/mariadb.pid
#
# include all files from the config directory
#
#!includedir /etc/my.cnf.d
~
:wq重启服务
[root@test222 ~]# vi /etc/my.cnf
[root@test222 ~]# /etc/init.d/mysqld restart
Shutting down MySQL.. SUCCESS!
Starting MySQL.. SUCCESS!
[root@test222 ~]# ls /data/mysql
test222.err test221.000001 auto.cnf ib_logfile0 localhost.localdomain.err mysql test
test222.pid test221.index ibdata1 ib_logfile1 localhost.localdomain.pid performance_schema保证和主从机器上的库数据一致
把主机器上备份的数据，拷贝到从机器上，然后做一个数据恢复
[root@test222 ~]# scp 172.16.22.221:/tmp/*.sql /tmp/
[email protected]'s password:
blog.sql 100% 787 0.8KB/s 00:00
my2.sql 100% 642KB 641.9KB/s 00:00
zrlog.sql 100% 10KB 9.8KB/s 00:00
[root@test222 ~]#
[root@test222 ~]# mysql -uroot
-bash: mysql: 未找到命令
未找到命令，是因为没有把mysql命令加入到$PATH环境变量里面
为了方便使用mysql服务，将mysql目录、mysqldump加入到环境变量里,
[root@test222 ~]# alias 'mysql=/usr/local/mysql/bin/mysql'
[root@test222 ~]# alias 'mysqldump=/usr/local/mysql/bin/mysqldump'
[root@test222 ~]# 进入mysql
[root@test222 ~]# mysql -uroot
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.6.36 MySQL Community Server (GPL)
Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> 创建4个库
mysql> create database testing;
Query OK, 1 row affected (0.00 sec)
mysql> create database zrlog;
Query OK, 1 row affected (0.00 sec)
mysql> create database blog;
Query OK, 1 row affected (0.00 sec)
mysql> create database mysql2;
Query OK, 1 row affected (0.00 sec)
mysql>
mysql> quit
Bye
[root@test222 ~]#
做一个恢复
[root@test222 ~]# mysql -uroot zrlog < /tmp/zrlog.sql
[root@test222 ~]# mysql -uroot testing < /tmp/zrlog.sql
[root@test222 ~]# mysql -uroot mysql2 < /tmp/my2.sql
[root@test222 ~]# mysql -uroot blog < /tmp/blog.sql
[root@test222 ~]# 对比下俩边的文件
从上面
[root@test222 ~]# ls /data/mysql
testing test221.000001 blog ib_logfile1 mysql test
test222.err test221.index ibdata1 localhost.localdomain.err mysql2 zrlog
test222.pid auto.cnf ib_logfile0 localhost.localdomain.pid performance_schema
[root@test222 ~]#
主上面
[root@test221 mysql]# ls
testing test221.index ib_logfile0 mysql test
test221.err auto.cnf ib_logfile1 mysql2 zrlog
test221.pid blog localhost.err performance_schema
test221.000001 ibdata1 localhost.localdomain.err
[root@test221 mysql]#
下面来实现主从
先进入mysql
[root@test222 ~]# mysql -uroot
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 6
Server version: 5.6.36 MySQL Community Server (GPL)
Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.stop slave;
mysql> stop slave;
Query OK, 0 rows affected, 1 warning (0.00 sec)
mysql> mysql> change master to master_host='172.16.22.221', master_user='repl', master_password='test22111', master_log_file='test221.000001',master_log_pos=10755;
Query OK, 0 rows affected, 2 warnings (0.02 sec)
mysql>
mysql> start slave;
Query OK, 0 rows affected (0.02 sec)
mysql> 这个时候怎么判定主从有没有设置成功呢
mysql> start slave;
Query OK, 0 rows affected (0.02 sec)
mysql> show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 172.16.22.221
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: test221.000001
Read_Master_Log_Pos: 10849
Relay_Log_File: test222-relay-bin.000002
Relay_Log_Pos: 285
Relay_Master_Log_File: test221.000001
Slave_IO_Running: Yes
Slave_SQL_Running: No
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 1007
Last_Error: Error 'Can't create database 'blog'; database exists' on query. Default database: 'blog'. Query: 'create database blog'
Skip_Counter: 0
Exec_Master_Log_Pos: 10755
Relay_Log_Space: 555
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Master_SSL_Allowed: No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master: NULL
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 1007
Last_SQL_Error: Error 'Can't create database 'blog'; database exists' on query. Default database: 'blog'. Query: 'create database blog'
Replicate_Ignore_Server_Ids:
Master_Server_Id: 221
Master_UUID: 69e8b25a-b0dd-11e7-997f-000c292e28f2
Master_Info_File: /data/mysql/master.info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State:
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp: 171107 23:15:40
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set:
Executed_Gtid_Set:
Auto_Position: 0
1 row in set (0.00 sec)
mysql> Slave_IO_Running: Yes 这个很重要，其中一个是NO就表示主从已经端口
Slave_SQL_Running: No 这个很重要，其中一个是NO就表示主从已经端口
这里Slave_SQL_Running: No，出错了，
解决办法
mysql> stop slave;
Query OK, 0 rows affected, 1 warning (0.00 sec)
mysql> set GLOBAL SQL_SLAVE_SKIP_COUNTER=1;
Query OK, 0 rows affected (0.00 sec)
mysql> start slave ;
Query OK, 0 rows affected (0.01 sec)
mysql> show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 172.16.22.221
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: test221.000002
Read_Master_Log_Pos: 120
Relay_Log_File: test222-relay-bin.000007
Relay_Log_Pos: 285
Relay_Master_Log_File: test221.000002
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 120
Relay_Log_Space: 626
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Master_SSL_Allowed: No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id: 221
Master_UUID: 69e8b25a-b0dd-11e7-997f-000c292e28f2
Master_Info_File: /data/mysql/master.info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Slave has read all relay log; waiting for the slave I/O thread to update it
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set:
Executed_Gtid_Set:
Auto_Position: 0
1 row in set (0.00 sec)
mysql>
恢复主机器上的表的写操作
unlock tables
mysql> unlock tables;
Query OK, 0 rows affected (0.00 sec)
mysql> 到此，主从就算搭建完了
17.5 测试主从同步
几个配置参数
主服务器上
binlog-do-db= //仅同步指定的库（多个库，可以用“ , ”逗号分隔）
binlog-ignore-db= //忽略指定库
从服务器上
replicate_do_db= //仅同步指定的库
replicate_ignore_db= //忽略指定库
replicate_do_table= //仅同步指定的库 建议用下面两条配置，请无视这条配置
replicate_ignore_table= //忽略指定库 建议用下面两条配置，请无视这条配置
replicate_wild_do_table= //如testing.%, 支持通配符% 指定同步靠谱的匹配 同步表 常用
replicate_wild_ignore_table= //如testing.%, 支持通配符% 指定同步靠谱的匹配 忽略表 常用
测试
主上进入mysql
切换到testing库
mysql> use testing;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql> 查看表
mysql> show tables;
+-----------------+
| Tables_in_testing |
+-----------------+
| comment |
| link |
| log |
| lognav |
| plugin |
| tag |
| type |
| user |
| website |
+-----------------+
9 rows in set (0.00 sec)
mysql> select count(*) user;
+------+
| user |
+------+
| 1 |
+------+
1 row in set (0.00 sec)
mysql> 再切换到从服务器上
mysql> use testing;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql> select count(*) user;
+------+
| user |
+------+
| 1 |
+------+
1 row in set (0.00 sec)
mysql> 也是一样的，数据是一致的
现在要把tag表做一个删除操作
mysql> truncate table tag;
Query OK, 0 rows affected (0.03 sec)
mysql> select count(*) tag;
+-----+
| tag |
+-----+
| 1 |
+-----+
1 row in set (0.00 sec)
mysql>
mysql> select * from tag;
Empty set (0.00 sec)
mysql> 再去从上看下
mysql> select count(*) tag;
+-----+
| tag |
+-----+
| 1 |
+-----+
1 row in set (0.00 sec)
mysql> select * from tag;
Empty set (0.00 sec)
mysql> 下面做一个操作，把表直接给删掉
mysql> show tables;
+-----------------+
| Tables_in_testing |
+-----------------+
| comment |
| link |
| log |
| lognav |
| plugin |
| tag |
| type |
| user |
| website |
+-----------------+
9 rows in set (0.00 sec)
mysql> drop table tag;
Query OK, 0 rows affected (0.03 sec)
mysql>
再去从上看
mysql> select * from tag;
ERROR 1146 (42S02): Table 'testing.tag' doesn't exist
mysql> 这就是主从同步
再来做个删除testing库
先去主上
mysql> drop database testing;
Query OK, 8 rows affected (0.15 sec)
mysql> 再去从上看，没有testing库了
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| blog |
| mysql |
| mysql2 |
| performance_schema |
| test |
| zrlog |
+--------------------+
7 rows in set (0.00 sec)
mysql> 因为意外在从机器上做了意外的删除，新增，更改操作，就可以可能导致“Slave_SQL_Running: NO”
如果出现了“Slave_SQL_Running: NO ” 需要去主上面，重新做一个“change master”的操作 比对主机器上的“master_log_pos=10755”，就可以恢复了
操作前需要先sotp slave
然后再
change master to master_host=’172.16.22.221′, master_user=’repl’, master_password=’aiker123456’,master_log_file=’Master.000001′, master_log_pos=10911;
如果遇到主从不能正常同步，提示uuid相同的错误。这是因为克隆机器导致。
配置mysql主从时，由于是拷贝的mysql目录，导致主从mysql uuid相同， Slave_IO无法启动，报错信息如下：
The slave I/O thread stops because master and slave have equal MySQL server UUIDs; these UUIDs must be different for replication to work.解决办法:修改mysql data 目录下auto.cnf 文件中uuid的值，使两台mysql不同即可，修改后重启mysql服务。