- 17.1 MySQL主從介紹
- 17.2 準備工作
- 17.3 配置主
- 17.4 配置從
- 17.5 測試主從同步

# 17.1 MySQL主從介紹
-  MySQL主從又叫做Replication、AB復制。簡單講就是A和B兩臺機器做主從後，在A上寫數據，另外一臺B也會跟著寫數據，兩者數據實時同步的
-  MySQL主從是基於binlog的，主上須開啟binlog才能進行主從。bilog，是二進制文件，無法cat
-  主從過程大致有3個步驟
1. 主將更改操作記錄到binlog裏
2. 從將主的binlog事件(sql語句)同步到從本機上並記錄在relaylog裏；relaylog，中繼日誌
3. 從根據relaylog裏面的sql語句按順序執行
-  主上有一個log dump線程，用來和從的I/O線程傳遞binlog
-  從上有兩個線程，其中I/O線程用來同步主的binlog並生成relaylog，另外一個SQL線程用來把relaylog裏面的sql語句落地
- mysql原理圖

-  使用場景：
- 一、數據備份，主機器宕機，從機器還能隨時對web提供服務
- 二、數據備份且可以分擔主機器被調用數據時的壓力，mysql主從，是有方向性的，寫數據，必須從主機器開始；如果不依照原理會導致數據紊亂











# 17.2 準備工作

- 主從配置，主上操作
- mysql安裝總結
- 進入src專用的下載目錄下，下載mysql二進制免編譯包
- wget 5.6版本，x64位
- 解壓
- tar zxvf 。。。
- 移動
- mv 。。 /usr/local/mysql
- 移動時，需註意這個目錄是否已經存在，如果存在了，需要刪除舊文件
- 初始化配置
- 進入所在的mysql目錄
```
[root@aming-01 mysql]# pwd
/usr/local/mysql
./scripts/mysql_install_db –user=mysql –datadir=/data/mysql
–user=mysql 需提前創建
```
- 編輯my.cnf文件（7版本的centos系統，就自帶安裝一個mariadb，所以就會自動生成有一個my.cnf，就省去了拷貝）
```
vim /etc/my.cnf   //添加以下兩行內容
datadir=/data/mysql     
socket=/tmp/mysql.sock
```
- 拷貝啟動腳本 cp support-files/mysql.server /etc/init.d/mysqld 
- 編輯啟動腳本
vim /etc/init.d/mysqld //對以下兩行進行指定路徑
basedir=
datadir=
指定basedir的路徑 /usr/local/mysql  
指定datadir的路徑 /data/mysql

- 最重要的一步，記得查看/data/mysql 的默認屬主、屬組，如果不是mysql的，啟東時會因為無法寫入數據而不能啟動

- chomd mysql:mysql /data/mysql

- 然後就可以嘗試啟動
/etc/init.d/mysql start


- [x] 主機器
- 192.168.202.131
- mysql啟動情況
```
[root@aming-01 ~]# ps aux |grep mysql
root        941  0.0  0.1 115392  1688 ?        S    20:14   0:00 /bin/sh /usr/local/mysql/bin/mysqld_safe --datadir=/data/mysql --pid-file=/data/mysql/aming-01.pid
mysql      1347  1.3 45.3 1300816 452976 ?      Sl   20:14   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/aming-01.err --pid-file=/data/mysql/aming-01.pid --socket=/tmp/mysql.sock
root       2353  0.0  0.0 112684   980 pts/0    S+   20:17   0:00 grep --color=auto mysql
[root@aming-01 ~]# 
```
- [x] 從機器
- 192.168.202.132
- mysql啟動情況
```
[root@aming-02 ~]# ps aux |grep mysql
root       1074  0.0  0.1 115392  1680 ?        S    20:15   0:00 /bin/sh /usr/local/mysql/bin/mysqld_safe --datadir=/data/mysql --pid-file=/data/mysql/aming-02.pid
mysql      1523  1.7 45.2 1300784 452076 ?      Sl   20:15   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/aming-02.err --pid-file=/data/mysql/aming-02.pid --socket=/tmp/mysql.sock
root       2284  0.0  0.0 112680   980 pts/0    S+   20:17   0:00 grep --color=auto mysql
[root@aming-02 ~]# 
```







# 17.3 配置主
-  安裝mysql
-  修改my.cnf，增加server-id=131和log_bin=aminglinux1
-  修改完配置文件後，啟動或者重啟mysqld服務
-  把mysql庫備份並恢復成aming庫，作為測試數據
-  mysqldump -uroot mysql > /tmp/mysql.sql
-  mysql -uroot -e “create database aming”
-  mysql -uroot aming < /tmp/mysql.sql
-  創建用作同步數據的用戶
-  grant replication slave on *.* to ‘repl‘@slave_ip identified by ‘password‘;
-  flush tables with read lock;
-  show master status;

- 修改主機器上的配置文件
```
[root@aming-01 ~]# 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
```
- 更改為
```
[root@aming-01 ~]# vi /etc/my.cnf

[mysqld]
datadir=/data/mysql
socket=/tmp/mysql.sock
server-id=131
log_bin=aminglinux1
# 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
```
- 修改之後要重啟mysql,進入/data/mysql/目錄下
```
[root@aming-01 ~]# /etc/init.d/mysqld restart
Shutting down MySQL.. SUCCESS! 
Starting MySQL.. SUCCESS! 
[root@aming-01 ~]# 

[root@aming-01 ~]# pwd
/root
[root@aming-01 ~]# cd /data/mysql
[root@aming-01 mysql]# ls -lt
總用量 110768
-rw-rw----. 1 mysql mysql 50331648 11月  7 21:44 ib_logfile0
-rw-rw----. 1 mysql mysql 12582912 11月  7 21:44 ibdata1
-rw-rw----. 1 mysql mysql    29700 11月  7 21:43 aming-01.err
-rw-rw----. 1 mysql mysql        5 11月  7 21:43 aming-01.pid
-rw-rw----. 1 mysql mysql       21 11月  7 21:43 aminglinux1.index
-rw-rw----. 1 mysql mysql      120 11月  7 21:43 aminglinux1.000001
drwx------. 2 mysql mysql     4096 11月  6 22:12 zrlog
-rw-rw----. 1 mysql mysql    44847 10月 31 22:02 localhost.err
drwx------. 2 mysql mysql     4096 10月 30 23:13 mysql2
-rw-rw----. 1 mysql mysql    15630 10月 25 23:10 www.qq123.com.err
-rw-rw----. 1 mysql mysql    49405 10月 24 23:57 localhost.localdomain.err
-rw-rw----. 1 mysql mysql       56 10月 14 20:44 auto.cnf
drwx------. 2 mysql mysql     4096 10月 14 20:31 mysql
drwx------. 2 mysql mysql     4096 10月 14 20:31 performance_schema
-rw-rw----. 1 mysql mysql 50331648 10月 14 20:31 ib_logfile1
drwx------. 2 mysql mysql        6 10月 14 20:31 test
[root@aming-01 mysql]# 

```
- .index  索引頁，這個文件是必須要有的
- .000001 這個是二進制日誌文件，會持續生成2、3、4等等（這個文件是實現主從配置的根本，沒有這個文件根本沒有辦法實現）
- 第二步，準備一個數據，做演示用的，重新來搞一個數據出來，在blog基礎上備份一個出來
```
[root@aming-01 mysql]# ls -lt
總用量 110768
-rw-rw----. 1 mysql mysql 50331648 11月  7 21:44 ib_logfile0
-rw-rw----. 1 mysql mysql 12582912 11月  7 21:44 ibdata1
-rw-rw----. 1 mysql mysql    29700 11月  7 21:43 aming-01.err
-rw-rw----. 1 mysql mysql        5 11月  7 21:43 aming-01.pid
-rw-rw----. 1 mysql mysql       21 11月  7 21:43 aminglinux1.index
-rw-rw----. 1 mysql mysql      120 11月  7 21:43 aminglinux1.000001
drwx------. 2 mysql mysql     4096 11月  6 22:12 zrlog
-rw-rw----. 1 mysql mysql    44847 10月 31 22:02 localhost.err
drwx------. 2 mysql mysql     4096 10月 30 23:13 mysql2
-rw-rw----. 1 mysql mysql    15630 10月 25 23:10 www.qq123.com.err
-rw-rw----. 1 mysql mysql    49405 10月 24 23:57 localhost.localdomain.err
-rw-rw----. 1 mysql mysql       56 10月 14 20:44 auto.cnf
drwx------. 2 mysql mysql     4096 10月 14 20:31 mysql
drwx------. 2 mysql mysql     4096 10月 14 20:31 performance_schema
-rw-rw----. 1 mysql mysql 50331648 10月 14 20:31 ib_logfile1
drwx------. 2 mysql mysql        6 10月 14 20:31 test
[root@aming-01 mysql]# mysqldump -uroot -paminglinux zrlog > /tmp/zrlog.sql
Warning: Using a password on the command line interface can be insecure.
[root@aming-01 mysql]# 
[root@aming-01 mysql]# du -sh /tmp/zrlog.sql
12K	/tmp/zrlog.sql
[root@aming-01 mysql]# 
```
- 新創建一個庫,叫aming的庫
```
[root@aming-01 mysql]# mysql -uroot -paminglinux -e "create database aming"
Warning: Using a password on the command line interface can be insecure.
[root@aming-01 mysql]# 
```
- 創建庫之後還需要把這個數據恢復一下
```
[root@aming-01 mysql]# mysql -uroot -paminglinux aming < /tmp/zrlog.sql
Warning: Using a password on the command line interface can be insecure.
[root@aming-01 mysql]# 
```
- 現在要做的主從，參考的對象就是這個庫 aming這個庫
```
[root@aming-01 mysql]# ls -lt
總用量 225468
-rw-rw----. 1 mysql mysql 50331648 11月  7 21:56 ib_logfile0
-rw-rw----. 1 mysql mysql 79691776 11月  7 21:56 ibdata1
-rw-rw----. 1 mysql mysql    10543 11月  7 21:56 aminglinux1.000001
drwx------. 2 mysql mysql     4096 11月  7 21:56 aming
-rw-rw----. 1 mysql mysql    29700 11月  7 21:43 aming-01.err
-rw-rw----. 1 mysql mysql        5 11月  7 21:43 aming-01.pid
-rw-rw----. 1 mysql mysql       21 11月  7 21:43 aminglinux1.index
drwx------. 2 mysql mysql     4096 11月  6 22:12 zrlog
-rw-rw----. 1 mysql mysql    44847 10月 31 22:02 localhost.err
drwx------. 2 mysql mysql     4096 10月 30 23:13 mysql2
-rw-rw----. 1 mysql mysql    15630 10月 25 23:10 www.qq123.com.err
-rw-rw----. 1 mysql mysql    49405 10月 24 23:57 localhost.localdomain.err
-rw-rw----. 1 mysql mysql       56 10月 14 20:44 auto.cnf
drwx------. 2 mysql mysql     4096 10月 14 20:31 mysql
drwx------. 2 mysql mysql     4096 10月 14 20:31 performance_schema
-rw-rw----. 1 mysql mysql 50331648 10月 14 20:31 ib_logfile1
drwx------. 2 mysql mysql        6 10月 14 20:31 test
[root@aming-01 mysql]# 

```

- 先進入到mysql裏面來
```
[root@aming-01 mysql]# mysql -uroot -paminglinux
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> 

```
- 創建用作同步數據的用戶
```

mysql> grant replication slave on *.* to ‘repl‘@‘192.168.202.132‘ identified by ‘aminglinux111‘;
Query OK, 0 rows affected (0.00 sec)

mysql> 
```
- 不要忘記給它鎖上，目的是不要再讓它繼續寫了
- 鎖表的目的是不讓表繼續寫，因為一會需要做從機器配置，需要進行一個同步，讓兩臺機器同步，保證兩臺機器的數據一致，同步才不會出錯
```
mysql> flush tables with read lock;
Query OK, 0 rows affected (0.00 sec)

mysql> 
```
- 做一個show master status；
```
mysql> show master status;
+--------------------+----------+--------------+------------------+-------------------+
| File               | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+--------------------+----------+--------------+------------------+-------------------+
| aminglinux1.000001 |    10755 |              |                  |                   |
+--------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)

mysql> 
mysql> quit
Bye
[root@aming-01 mysql]# 

```
- 需要記住binlog的filename，記住file 的位置，一會兒要用到它
- 一會兒要去從機器 上 同步這些庫 （高亮的為庫）
```
[root@aming-01 mysql]# ls
aming               aminglinux1.index  ib_logfile1                mysql2              zrlog
aming-01.err        auto.cnf           localhost.err              performance_schema
aming-01.pid        ibdata1            localhost.localdomain.err  test
aminglinux1.000001  ib_logfile0        mysql                      www.qq123.com.err
[root@aming-01 mysql]# 
[root@aming-01 mysql]# ls /tmp/zrlog.sql
/tmp/zrlog.sql
[root@aming-01 mysql]# 

```
- 把這下面的庫都做一個備份
```
[root@aming-01 mysql]# mysqldump -uroot -paminglinux mysql2 > /tmp/my2.sql
Warning: Using a password on the command line interface can be insecure.
[root@aming-01 mysql]# ls /tmp/*sql
/tmp/blog,sql  /tmp/blog.sql  /tmp/my2.sql  /tmp/zrlog.sql
[root@aming-01 mysql]# 
```












# 17.4 配置從
-  安裝mysql，已經做了
-  查看my.cnf，配置server-id=132，要求和主不一樣
-  修改完配置文件後，啟動或者重啟mysqld服務
-  把主上aming庫同步到從上
-  可以先創建aming庫，然後把主上的/tmp/mysql.sql拷貝到從上，然後導入aming庫
-  mysql -uroot
-  stop slave；
-  change master to master_host=‘‘, master_user=‘repl‘, master_password=‘‘, master_log_file=‘‘, master_log_pos=xx,
-  start slave;
-  還要到主上執行 unlock tables

- 進入/etc/my.cnf
```
[root@aming-02 ~]# vi /etc/my.cnf

[mysqld]
datadir=/data/mysql
socket=/tmp/mysql.sock
server-id=132
# 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
```
- 重啟服務
```
[root@aming-02 ~]# vi /etc/my.cnf
[root@aming-02 ~]# /etc/init.d/mysqld restart
Shutting down MySQL.. SUCCESS! 
Starting MySQL.. SUCCESS! 
[root@aming-02 ~]# ls /data/mysql
aming-02.err  aminglinux1.000001  auto.cnf  ib_logfile0  localhost.localdomain.err  mysql               test
aming-02.pid  aminglinux1.index   ibdata1   ib_logfile1  localhost.localdomain.pid  performance_schema
```
- 保證和主從機器上的庫數據一致
把主機器上備份的數據，拷貝到從機器上，然後做一個數據恢復
```
[root@aming-02 ~]# scp 192.168.202.131:/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@aming-02 ~]# 

[root@aming-02 ~]# mysql -uroot
-bash: mysql: 未找到命令

```
- 未找到命令，是因為沒有把mysql命令加入到$PATH環境變量裏面
- 為了方便使用mysql服務，將mysql目錄、mysqldump加入到環境變量裏,
```
[root@aming-02 ~]# alias ‘mysql=/usr/local/mysql/bin/mysql‘
[root@aming-02 ~]# alias ‘mysqldump=/usr/local/mysql/bin/mysqldump‘
[root@aming-02 ~]# 
```
- 進入mysql
```
[root@aming-02 ~]# 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> 
```
- 創建4個庫
```
mysql> create database aming;
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@aming-02 ~]# 


```
- 做一個恢復
```
[root@aming-02 ~]# mysql -uroot zrlog < /tmp/zrlog.sql
[root@aming-02 ~]# mysql -uroot aming < /tmp/zrlog.sql
[root@aming-02 ~]# mysql -uroot mysql2 < /tmp/my2.sql
[root@aming-02 ~]# mysql -uroot blog  < /tmp/blog.sql
[root@aming-02 ~]# 
```
- 對比下倆邊的文件
```
從上面
[root@aming-02 ~]# ls /data/mysql
aming         aminglinux1.000001  blog         ib_logfile1                mysql               test
aming-02.err  aminglinux1.index   ibdata1      localhost.localdomain.err  mysql2              zrlog
aming-02.pid  auto.cnf            ib_logfile0  localhost.localdomain.pid  performance_schema
[root@aming-02 ~]# 
主上面
[root@aming-01 mysql]# ls
aming               aminglinux1.index  ib_logfile0                mysql               www.qq123.com.err
aming-01.err        auto.cnf           ib_logfile1                mysql2              zrlog
aming-01.pid        blog               localhost.err              performance_schema
aminglinux1.000001  ibdata1            localhost.localdomain.err  test
[root@aming-01 mysql]# 

```
- 下面來實現主從
- 先進入mysql
```
[root@aming-02 ~]# 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=‘192.168.202.131‘, master_user=‘repl‘, master_password=‘aminglinux111‘, master_log_file=‘aminglinux1.000001‘,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> 
```
- 這個時候怎麽判定主從有沒有設置成功呢
```
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: 192.168.202.131
                  Master_User: repl
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: aminglinux1.000001
          Read_Master_Log_Pos: 10849
               Relay_Log_File: aming-02-relay-bin.000002
                Relay_Log_Pos: 285
        Relay_Master_Log_File: aminglinux1.000001
             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: 131
                  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     這個很重要，其中一個是NO就表示主從已經端口
            Slave_SQL_Running: No       這個很重要，其中一個是NO就表示主從已經端口

- 這裏Slave_SQL_Running: No，出錯了，
- 解決辦法
```
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: 192.168.202.131
                  Master_User: repl
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: aminglinux1.000002
          Read_Master_Log_Pos: 120
               Relay_Log_File: aming-02-relay-bin.000007
                Relay_Log_Pos: 285
        Relay_Master_Log_File: aminglinux1.000002
             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: 131
                  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> 

```


- 恢復主機器上的表的寫操作
unlock tables
```
mysql> unlock tables;
Query OK, 0 rows affected (0.00 sec)

mysql> 
```

- 到此，主從就算搭建完了









# 17.5 測試主從同步
- 幾個配置參數
- 主服務器上
-  binlog-do-db=            //僅同步指定的庫（多個庫，可以用“ , ”逗號分隔）
-  binlog-ignore-db=     //忽略指定庫
- 從服務器上
-  replicate_do_db=          //僅同步指定的庫
-  replicate_ignore_db=     //忽略指定庫
-  replicate_do_table=         //僅同步指定的庫  建議用下面兩條配置，請無視這條配置
-  replicate_ignore_table=    //忽略指定庫    建議用下面兩條配置，請無視這條配置
-  replicate_wild_do_table=   //如aming.%, 支持通配符%  指定同步靠譜的匹配  同步表    常用
-  replicate_wild_ignore_table=   //如aming.%, 支持通配符%  指定同步靠譜的匹配  忽略表    常用
- 測試
主上進入mysql
切換到aming庫
```
mysql> use aming;
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_aming |
+-----------------+
| 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> 
```
- 再切換到從服務器上
```
mysql> use aming;
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> 
```
- 也是一樣的，數據是一致的
- 現在要把tag表做一個刪除操作
```
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> 
```
- 再去從上看下
```
mysql> select count(*) tag;
+-----+
| tag |
+-----+
|   1 |
+-----+
1 row in set (0.00 sec)

mysql> select * from tag;
Empty set (0.00 sec)

mysql> 
```
- 下面做一個操作，把表直接給刪掉
```
mysql> show tables;
+-----------------+
| Tables_in_aming |
+-----------------+
| 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> 

```
- 再去從上看
```
mysql> select * from tag;
ERROR 1146 (42S02): Table ‘aming.tag‘ doesn‘t exist
mysql> 
```
- 這就是主從同步
- 再來做個刪除aming庫
- 先去主上
```
mysql> drop database aming;
Query OK, 8 rows affected (0.15 sec)

mysql> 
```
- 再去從上看，沒有aming庫了
```
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| blog               |
| mysql              |
| mysql2             |
| performance_schema |
| test               |
| zrlog              |
+--------------------+
7 rows in set (0.00 sec)

mysql> 
```
- [x] 因為意外在從機器上做了意外的刪除，新增，更改操作，就可以可能導致“Slave_SQL_Running: NO”
- 如果出現了“Slave_SQL_Running: NO ” 需要去主上面，重新做一個“change master”的操作 比對主機器上的“master_log_pos=10755”，就可以恢復了
- 操作前需要先sotp slave
- 然後再
- change master to master_host=’192.168.133.131′, master_user=’repl’, master_password=’aminglinux’,master_log_file=’Master.000001′, master_log_pos=10911;

17.1 MySQL主從介紹17.2 準備工作17.3 配置主17.4 配置從17.5 測試主從同步