企业级 ##MySQL 5.7 数据库多台主从复制 基于GTID主从复制 半同步##

主从复制的基本概念：

1.主从复制的条件：
实时灾备，用于故障切换读写分离，提供查询服务备份，避免影响业务
2.主从复制原理：
从库生成两个线程，一个i/o线程，一个SQL线程；i/o线程去请求主库的binlog，并且得到的binlog日志写道relay log(中继日志)文件中，主库会生成一个log dump线程，用来给从库的i/o线程传binlog；SQL线程，会读取中继日志文件，并解析成具体的操作执行，这样主从的操作就一致了，而最终的数据也就一直了。
3.主从复制存在的问题以及解决办法：
主库宕机之后，数据可能会丢失从库只有一个sql Thread，主库写压力大，复制很可能延时
解决方法：
半同步复制解决–解决数据丢失的问题并行复制–解决从库复制延时的问题
【server1】 master IP:172.25.48.1【server2】 slave IP:172.25.48.2
注: mysql 数据库的版本,两个数据库版本要相同,或者 slave 比 master 版本高!

---

一.配置安装数据库：

【server1】主库配置

1.下载安装包：

mysql-community-client.x86_64 0:5.7.17-1.el6                                          
  mysql-community-common.x86_64 0:5.7.17-1.el6                                          
  mysql-community-libs.x86_64 0:5.7.17-1.el6                                            
  mysql-community-libs-compat.x86_64 0:5.7.17-1.el6                                     
  mysql-community-server.x86_64 0:5.7.17-1.el6   

2.配置文件,添加数据库ID：

[root@server1 ~]# vim /etc/my.cnf

server-id=1
log-bin=mysql-bin

[root@server1 ~]# /etc/init.d/mysqld start
Initializing MySQL database:                               [  OK  ]
Installing validate password plugin:                       [  OK  ]
Starting mysqld:                                           [  OK  ]

3.初始化数据库：

[root@server1 ~]# grep password /var/log/mysqld.log 
2018-08-08T08:41:49.496479Z 1 [Note] A temporary password is generated for root@localhost: 1pVt3VzrL,IB
[root@server1 ~]# mysql_secure_installation 

Securing the MySQL server deployment.

Enter password for user root: 

The existing password for the user account root has expired. Please set a new password.

New password: 

Re-enter new password: 
The 'validate_password' plugin is installed on the server.
The subsequent steps will run with the existing configuration
of the plugin.
Using existing password for root.

Estimated strength of the password: 100 
Change the password for root ? ((Press y|Y for Yes, any other key for No) : 

 ... skipping.
By default, a MySQL installation has an anonymous user,
allowing anyone to log into MySQL without having to have
a user account created for them. This is intended only for
testing, and to make the installation go a bit smoother.
You should remove them before moving into a production
environment.

Remove anonymous users? (Press y|Y for Yes, any other key for No) : y
Success.


Normally, root should only be allowed to connect from
'localhost'. This ensures that someone cannot guess at
the root password from the network.

Disallow root login remotely? (Press y|Y for Yes, any other key for No) : y
Success.

By default, MySQL comes with a database named 'test' that
anyone can access. This is also intended only for testing,
and should be removed before moving into a production
environment.


Remove test database and access to it? (Press y|Y for Yes, any other key for No) : 

 ... skipping.
Reloading the privilege tables will ensure that all changes
made so far will take effect immediately.

Reload privilege tables now? (Press y|Y for Yes, any other key for No) : y
Success.

All done! 

4.登陆数据库：

[root@server1 ~]# mysql -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 15
Server version: 5.7.17-log MySQL Community Server (GPL)

Copyright (c) 2000, 2016, 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> 

5.给登陆用户可复制权限：

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
4 rows in set (0.00 sec)

mysql> grant replication slave on *.* to repl@'172.25.39.%' identified by 'Xa85215295##';
Query OK, 0 rows affected, 1 warning (0.06 sec)
mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000003 |      843 |              |                  |                   |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)

6.【server2】用repl测试登陆

[root@server2 ~]# mysql -u repl -p -h 172.25.39.1
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 16
Server version: 5.7.17-log MySQL Community Server (GPL)

Copyright (c) 2000, 2016, 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> 

【server2】从库配置

1.配置文件,添加数据库ID：
从服务器 ID 号,不要和主 ID 相同,如果设置多个从服务器,每个从服务器必须有一个唯一的 server-id 值,必须与主服务器的以及其它从服务器的不相同。可以认为 server-id 值类似于 IP 地址:这些 ID 值能唯一识别复制服务器群集中的每个服务器实例。

[root@server2 ~]# vim /etc/my.cnf
server-id=2
[root@server2 ~]# /etc/init.d/mysqld start
Starting mysqld:                                           [  OK  ]

2.初始化数据库：

[root@server2 ~]# grep password /var/log/mysqld.log
2018-08-08T09:03:10.015626Z 1 [Note] A temporary password is generated for root@localhost: ya3W5pslkk,f

[root@server2 ~]# mysql_secure_installation 

Securing the MySQL server deployment.

Enter password for user root: 

The existing password for the user account root has expired. Please set a new password.

New password: 

Re-enter new password: 
The 'validate_password' plugin is installed on the server.
The subsequent steps will run with the existing configuration
of the plugin.
Using existing password for root.

Estimated strength of the password: 100 
Change the password for root ? ((Press y|Y for Yes, any other key for No) : 

 ... skipping.
By default, a MySQL installation has an anonymous user,
allowing anyone to log into MySQL without having to have
a user account created for them. This is intended only for
testing, and to make the installation go a bit smoother.
You should remove them before moving into a production
environment.

Remove anonymous users? (Press y|Y for Yes, any other key for No) : y
Success.


Normally, root should only be allowed to connect from
'localhost'. This ensures that someone cannot guess at
the root password from the network.

Disallow root login remotely? (Press y|Y for Yes, any other key for No) : y
Success.

By default, MySQL comes with a database named 'test' that
anyone can access. This is also intended only for testing,
and should be removed before moving into a production
environment.


Remove test database and access to it? (Press y|Y for Yes, any other key for No) : 

 ... skipping.
Reloading the privilege tables will ensure that all changes
made so far will take effect immediately.

Reload privilege tables now? (Press y|Y for Yes, any other key for No) : y
Success.

All done! 

2.在【server2】中添加与主库连接,查看与主库是否联通：

mysql>  change master to master_host='172.25.39.1',master_user='repl',master_password='Xa85215295##',master_log_file='mysql-bin.000003',master_log_pos=843;
Query OK, 0 rows affected, 2 warnings (0.71 sec)

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: 172.25.39.1
                  Master_User: repl
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000003
          Read_Master_Log_Pos: 843
               Relay_Log_File: server2-relay-bin.000002
                Relay_Log_Pos: 320
        Relay_Master_Log_File: mysql-bin.000003
             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: 843
              Relay_Log_Space: 529
              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: 1
                  Master_UUID: e4071ad2-9ae6-11e8-9c2a-525400ed3db7
             Master_Info_File: /var/lib/mysql/master.info
                    SQL_Delay: 0
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
           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
         Replicate_Rewrite_DB: 
                 Channel_Name: 
           Master_TLS_Version: 
1 row in set (0.00 sec)

ERROR: 
No query specified

注意：
· 当看到Slave_IO_Running: Yes以及Slave_SQL_Running: Yes，则表示slave库已经正常运行了
· 当出现Slave_IO_Running: Connecting的提示时，说明主库和从库没有连接上，有以下三点原因：
· 1.网络问题：检查网络连接是否能够连接上
· 2.密码或POS号错误：查看pos号和主库的号是否对应
· 3.防火墙的问题：查看主库防火墙的策略，数据库是否拒绝外来连接，然后做相应的改动

二.添加主库数据进行测试：

1.【server1】主库添加数据：

mysql> create database  test;
Query OK, 1 row affected (0.41 sec)

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
| test               |
+--------------------+
5 rows in set (0.00 sec)

mysql> use test
Database changed
mysql> create table userlist(
    -> username varchar(15) not null,
    -> password varchar(25) not null);
Query OK, 0 rows affected (0.49 sec)
mysql> insert into userlist values ('user1','123');
Query OK, 1 row affected (0.14 sec)

mysql> insert into userlist values ('user2','344');
Query OK, 1 row affected (0.16 sec)

mysql> insert into userlist values ('user3','789');
Query OK, 1 row affected (0.11 sec)

2.【server2】从库查看数据：

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
| test               |
+--------------------+
5 rows in set (0.00 sec)

mysql> use test
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 * from userlist;
+----------+----------+
| username | password |
+----------+----------+
| user1    | 123      |
| user2    | 344      |
| user3    | 789      |
+----------+----------+
3 rows in set (0.00 sec)

---

GTID主从复制

1.在【server1】【server2】中配置：

[root@server1 ~]# vim /etc/my.cnf
gtid_mode=ON
enforce-gtid-consistency=true
[root@server1 ~]# /etc/init.d/mysqld restart
Stopping mysqld:                                           [  OK  ]
Starting mysqld:                                           [  OK  ]

2.开启【server2】从库,查看连接：

[root@server2 ~]# mysql -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 6
Server version: 5.7.17 MySQL Community Server (GPL)

Copyright (c) 2000, 2016, 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> show slave status\G;
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 172.25.39.1
                  Master_User: repl
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000004
          Read_Master_Log_Pos: 154
               Relay_Log_File: server2-relay-bin.000005
                Relay_Log_Pos: 367
        Relay_Master_Log_File: mysql-bin.000004
             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: 154
              Relay_Log_Space: 742
              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: 1
                  Master_UUID: e4071ad2-9ae6-11e8-9c2a-525400ed3db7
             Master_Info_File: /var/lib/mysql/master.info
                    SQL_Delay: 0
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
           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
         Replicate_Rewrite_DB: 
                 Channel_Name: 
           Master_TLS_Version: 
1 row in set (0.00 sec)

ERROR: 
No query specified
mysql> stop slave;
Query OK, 0 rows affected (0.03 sec)
mysql> change master to master_host='172.25.39.1',master_user='repl',master_password='Xa85215295##',MASTER_AUTO_POSITION=1;
Query OK, 0 rows affected, 2 warnings (0.35 sec)

mysql> start slave;
Query OK, 0 rows affected (0.07 sec)

mysql> show slave status\G;
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 172.25.39.1
                  Master_User: repl
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000004
          Read_Master_Log_Pos: 154
               Relay_Log_File: server2-relay-bin.000002
                Relay_Log_Pos: 367
        Relay_Master_Log_File: mysql-bin.000004
             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: 154
              Relay_Log_Space: 576
              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: 1
                  Master_UUID: e4071ad2-9ae6-11e8-9c2a-525400ed3db7
             Master_Info_File: /var/lib/mysql/master.info
                    SQL_Delay: 0
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
           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: 1
         Replicate_Rewrite_DB: 
                 Channel_Name: 
           Master_TLS_Version: 
1 row in set (0.00 sec)

ERROR: 
No query specified

3.在【server1】中删除user3数据,并在【server2】查看：
【server1】

mysql> use test
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> show tables;
+----------------+
| Tables_in_test |
+----------------+
| userlist       |
+----------------+
1 row in set (0.00 sec)

mysql> select * from userlist;
+----------+----------+
| username | password |
+----------+----------+
| user1    | 123      |
| user2    | 344      |
| user3    | 789      |
+----------+----------+
3 rows in set (0.00 sec)

mysql> delete from userlist where username='user3';
Query OK, 1 row affected (0.13 sec)

mysql> select * from userlist;
+----------+----------+
| username | password |
+----------+----------+
| user1    | 123      |
| user2    | 344      |
+----------+----------+
2 rows in set (0.00 sec)

【server2】

mysql> use test
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 * from userlist;
+----------+----------+
| username | password |
+----------+----------+
| user1    | 123      |
| user2    | 344      |
+----------+----------+
2 rows in set (0.00 sec)

---

建立多个从库：

首先先搭建【server5】主库,【server6】从库的GTID主从复制
给三台虚拟机都安装数据库包
一.搭建第二个【server7】从库：
（以【server6】为主库,这样可以减少【server5】数据库的负载）
1.配置【server6】：vim /etc/my.cnf
添加：

log-bin=mysql-bin
log-slave-updates

2.重启数据库：
登陆数据库,查看连接状态,保证【server6】与【server5】没有断开连接

[root@server6 ~]# /etc/init.d/mysqld restart
Stopping mysqld:                                           [  OK  ]
Starting mysqld:                                           [  OK  ]

3.配置【server7】：vim /etc/my.cnf
重启数据库

添加：
server-id=7

gtid_mode=ON
enforce-gtid-consistency=true

4.登陆【server7】数据库,进行初始化并修改密码
5.在【server6】中添加‘172.25.39.%’网段用户的复制查看权限：

mysql> grant replication slave on *.* to repl@'172.25.39.%' identified by 'Xa85215295##'；
Query OK, 0 rows affected, 1 warning (0.05 sec)
mysql> show master status;
+------------------+----------+--------------+------------------+--------------------------------------------------------------------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set                                                              |
+------------------+----------+--------------+------------------+--------------------------------------------------------------------------------+
| mysql-bin.000001 |      447 |              |                  | 7b4cea55-9c4d-11e8-8955-525400f9cbe2:1,
b6801fd0-9c4a-11e8-b227-525400b9273c:1 |
+------------------+----------+--------------+------------------+--------------------------------------------------------------------------------+
1 row in set (0.00 sec)

6.先将【server6】中的数据发送到【server7】中,使数据同步,再进行下一步,不然首先数据都不同步,没法进行后续操作

[root@server6 ~]# mysqldump -p test > test.sql
Enter password: 
Warning: A partial dump from a server that has GTIDs will by default include the GTIDs of all transactions, even those that changed suppressed parts of the database. If you don't want to restore GTIDs, pass --set-gtid-purged=OFF. To make a complete dump, pass --all-databases --triggers --routines --events. 
[root@server6 ~]# ls
anaconda-ks.cfg  install.log  install.log.syslog  mysql  test.sql
[root@server6 ~]# scp test.sql  [email protected]:/root
The authenticity of host '172.25.39.7 (172.25.39.7)' can't be established.
RSA key fingerprint is ce:b7:35:21:60:9f:f3:8d:f4:25:af:73:ad:ad:bc:ab.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '172.25.39.7' (RSA) to the list of known hosts.
root@172.25.39.7's password: 
test.sql                                      100% 2177     2.1KB/s   00:00

7.在【server7】中查看test.sql脚本,并在脚本中添加配置建立数据库

[root@server7 ~]# vim test.sql

8.把刚才传过来的数据在【server7】中导入到数据库中,并进行数据查看

[root@server7 ~]# mysql -p < test.sql
Enter password: 
[root@server7 ~]# mysql -pXa85215295##
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
| test               |
+--------------------+
5 rows in set (0.00 sec)
mysql> use test
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 * from userlist;
+----------+----------+
| username | password |
+----------+----------+
| user1    | 123      |
| user2    | 123      |
+----------+----------+
2 rows in set (0.00 sec)    ##数据相同，初步环境同步成功

9.在【server7】从库中添加和【server6】主库的连接,有两个yes表示连接成功

mysql> change master to master_host='172.25.39.6',master_user='repl',master_password='Xa85215295##',master_auto_position=1;
Query OK, 0 rows affected, 2 warnings (0.55 sec)

mysql> start slave;
Query OK, 0 rows affected (0.03 sec)

mysql> show slave status\G;
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 172.25.39.6
                  Master_User: repl
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000001
          Read_Master_Log_Pos: 447
               Relay_Log_File: server7-relay-bin.000002
                Relay_Log_Pos: 414
        Relay_Master_Log_File: mysql-bin.000001
             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: 447
              Relay_Log_Space: 623
              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: 6
                  Master_UUID: b6801fd0-9c4a-11e8-b227-525400b9273c
             Master_Info_File: /var/lib/mysql/master.info
                    SQL_Delay: 0
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
           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: 7b4cea55-9c4d-11e8-8955-525400f9cbe2:1,
b6801fd0-9c4a-11e8-b227-525400b9273c:1
                Auto_Position: 1
         Replicate_Rewrite_DB: 
                 Channel_Name: 
           Master_TLS_Version: 
1 row in set (0.00 sec)

ERROR: 
No query specified

10.测试连接：
（1）在【server5】主库中添加新的数据：

[root@server5 ~]# mysql -pXa85215295##
mysql> use test
mysql> insert into test.userlist  values ('user3','333');
Query OK, 1 row affected (0.08 sec)

mysql> select * from userlist;
+----------+----------+
| username | password |
+----------+----------+
| user1    | 123      |
| user2    | 123      |
| user3    | 333      |
+----------+----------+
3 rows in set (0.00 sec)

（2）在【server7】中查看刚才在【server5】中添加的数据：

[root@server7 ~]# mysql -pXa85215295##
mysql> use test
mysql> select * from userlist;
+----------+----------+
| username | password |
+----------+----------+
| user1    | 123      |
| user2    | 123      |
| user3    | 333      |
+----------+----------+
3 rows in set (0.00 sec)

---

并行复制

【server6】 登陆mysql数据库：

配置文件,添加并行复制：

[root@server6 ~]# vim /etc/my.cnf
[root@server6 ~]# /etc/init.d/mysqld restart
Stopping mysqld:                                           [  OK  ]
Starting mysqld:                                           [  OK  ]

添加：

【server6】 再次登陆mysql数据库：没有延时

---

Mysql半同步

介于异步复制和全同步复制之间，主库在执行完客户端提交的事务后不是立刻返回给客户端，而是等待至少一个从库接收到并写到relay log中才返回给客户端。相对于异步复制，半同步复制提高了数据的安全性，同时它也造成了一定程度的延迟，这个延迟最少是一个TCP/IP往返的时间。所以，半同步复制最好在低延时的网络中使用。

1.【server5】主库加载mater模块：

mysql> install plugin rpl_semi_sync_master soname 'semisync_master.so';
Query OK, 0 rows affected (0.12 sec)           ##安装插件

mysql> set global rpl_semi_sync_master_enabled=ON;
Query OK, 0 rows affected (0.00 sec)           ##启动半同步复制

mysql> show variables like '%semi%';       #环境变量
+-------------------------------------------+------------+
| Variable_name                             | Value      |
+-------------------------------------------+------------+
| rpl_semi_sync_master_enabled              | ON         |
| rpl_semi_sync_master_timeout              | 10000      |
| rpl_semi_sync_master_trace_level          | 32         |
| rpl_semi_sync_master_wait_for_slave_count | 1          |
| rpl_semi_sync_master_wait_no_slave        | ON         |
| rpl_semi_sync_master_wait_point           | AFTER_SYNC |
+-------------------------------------------+------------+
6 rows in set (0.04 sec)

mysql> show status like '%rpl_semi_sync%';      ##状态变量
+--------------------------------------------+-------+
| Variable_name                              | Value |
+--------------------------------------------+-------+
| Rpl_semi_sync_master_clients               | 0     |
| Rpl_semi_sync_master_net_avg_wait_time     | 0     |
| Rpl_semi_sync_master_net_wait_time         | 0     |
| Rpl_semi_sync_master_net_waits             | 0     |
| Rpl_semi_sync_master_no_times              | 0     |
| Rpl_semi_sync_master_no_tx                 | 0     |
| Rpl_semi_sync_master_status                | ON    |##半同步master模块开启
| Rpl_semi_sync_master_timefunc_failures     | 0     |
| Rpl_semi_sync_master_tx_avg_wait_time      | 0     |
| Rpl_semi_sync_master_tx_wait_time          | 0     |
| Rpl_semi_sync_master_tx_waits              | 0     |
| Rpl_semi_sync_master_wait_pos_backtraverse | 0     |
| Rpl_semi_sync_master_wait_sessions         | 0     |
| Rpl_semi_sync_master_yes_tx                | 0     |
+--------------------------------------------+-------+
14 rows in set (0.00 sec)

2.【server6】既是主库,也是从库,所以模块都需要加载：

[root@server6 ~]# mysql -pXa85215295##
mysql> show slave status\G;
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 172.25.39.5
                  Master_User: repl
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000004
          Read_Master_Log_Pos: 464
               Relay_Log_File: server6-relay-bin.000007
                Relay_Log_Pos: 414
        Relay_Master_Log_File: mysql-bin.000004
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes

mysql> stop slave;
Query OK, 0 rows affected (0.14 sec)

mysql> install plugin rpl_semi_sync_slave soname 'semisync_slave.so';
Query OK, 0 rows affected (0.08 sec)
#安装slave插件
mysql> install plugin rpl_semi_sync_master soname 'semisync_master.so';
Query OK, 0 rows affected (0.06 sec)
#安装master插件
mysql> set global rpl_semi_sync_master_enabled=ON;
Query OK, 0 rows affected (0.00 sec)
#启动半同步复制
mysql> set global rpl_semi_sync_slave_enabled=ON;
Query OK, 0 rows affected (0.00 sec)

mysql> show variables like '%semi%';     #环境变量
+-------------------------------------------+------------+
| Variable_name                             | Value      |
+-------------------------------------------+------------+
| rpl_semi_sync_master_enabled              | ON         |
| rpl_semi_sync_master_timeout              | 10000      |
| rpl_semi_sync_master_trace_level          | 32         |
| rpl_semi_sync_master_wait_for_slave_count | 1          |
| rpl_semi_sync_master_wait_no_slave        | ON         |
| rpl_semi_sync_master_wait_point           | AFTER_SYNC |
| rpl_semi_sync_slave_enabled               | ON         |
| rpl_semi_sync_slave_trace_level           | 32         |
+-------------------------------------------+------------+
8 rows in set (0.00 sec)

mysql> start slave;
Query OK, 0 rows affected (0.59 sec)

mysql> stop slave io_thread;
Query OK, 0 rows affected (0.08 sec)

mysql> start slave io_thread;
Query OK, 0 rows affected (0.00 sec)
# 重启从上的IO线程,如果没有重启，则默认还是异步复制，重启后，slave会在master上注册为半同步复制的slave角色。
mysql> show status like '%rpl_semi_sync%';
+--------------------------------------------+-------+
| Variable_name                              | Value |
+--------------------------------------------+-------+
| Rpl_semi_sync_master_clients               | 0     |
| Rpl_semi_sync_master_net_avg_wait_time     | 0     |
| Rpl_semi_sync_master_net_wait_time         | 0     |
| Rpl_semi_sync_master_net_waits             | 0     |
| Rpl_semi_sync_master_no_times              | 0     |
| Rpl_semi_sync_master_no_tx                 | 0     |
| Rpl_semi_sync_master_status                | ON    |##半同步master模块开启
| Rpl_semi_sync_master_timefunc_failures     | 0     |  (   主库   )  
| Rpl_semi_sync_master_tx_avg_wait_time      | 0     |
| Rpl_semi_sync_master_tx_wait_time          | 0     |
| Rpl_semi_sync_master_tx_waits              | 0     |
| Rpl_semi_sync_master_wait_pos_backtraverse | 0     |
| Rpl_semi_sync_master_wait_sessions         | 0     |
| Rpl_semi_sync_master_yes_tx                | 0     |
| Rpl_semi_sync_slave_status                 | ON    |##半同步master模块开启
+--------------------------------------------+-------+   (   从库   )
15 rows in set (0.00 sec)

3.【server7】从库加载mater模块安装插件：

mysql> stop slave;
Query OK, 0 rows affected (0.05 sec)

mysql> install plugin rpl_semi_sync_slave soname 'semisync_slave.so';
Query OK, 0 rows affected (0.05 sec)

mysql> set global rpl_semi_sync_slave_enabled=ON;
Query OK, 0 rows affected (0.00 sec)    #启动半同步复制,也可写到配置文件中

mysql> start slave;
Query OK, 0 rows affected (0.03 sec)

mysql> select plugin_name,plugin_status
    -> from information_schema.plugins
    -> where plugin_name like '%semi%';
+---------------------+---------------+
| plugin_name         | plugin_status |
+---------------------+---------------+
| rpl_semi_sync_slave | ACTIVE        |
+---------------------+---------------+
1 row in set (0.00 sec)

4.进行测试：
（1）首先在【server5】master上查看以下参数,半同步是否正常开启：

mysql> show status like '%rpl_semi_sync%';
+--------------------------------------------+-------+
| Variable_name                              | Value |
+--------------------------------------------+-------+
| Rpl_semi_sync_master_clients               | 1     |
| Rpl_semi_sync_master_net_avg_wait_time     | 0     |
| Rpl_semi_sync_master_net_wait_time         | 0     |
| Rpl_semi_sync_master_net_waits             | 0     |
| Rpl_semi_sync_master_no_times              | 0     |
| Rpl_semi_sync_master_no_tx                 | 0     |
| Rpl_semi_sync_master_status                | ON    |  ##开启半同步
| Rpl_semi_sync_master_timefunc_failures     | 0     |
| Rpl_semi_sync_master_tx_avg_wait_time      | 0     |
| Rpl_semi_sync_master_tx_wait_time          | 0     |
| Rpl_semi_sync_master_tx_waits              | 0     |
| Rpl_semi_sync_master_wait_pos_backtraverse | 0     |
| Rpl_semi_sync_master_wait_sessions         | 0     |
| Rpl_semi_sync_master_yes_tx                | 0     |
+--------------------------------------------+-------+
14 rows in set (0.00 sec)

（2）然后【server6】slave上关闭io_thread线程：

mysql> stop slave io_thread;
Query OK, 0 rows affected (0.04 sec)

（3）在【server5】master上添加新的数据：

mysql> use test;
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> insert into test.userlist values ('user5','3333');
Query OK, 1 row affected (10.13 sec)

mysql> insert into test.userlist values ('user6','4444');
Query OK, 1 row affected (0.11 sec)

mysql> select * from userlist;
+----------+----------+
| username | password |
+----------+----------+
| user1    | 123      |
| user2    | 123      |
| user3    | 333      |
| user5    | 3333     |
| user6    | 4444     |
+----------+----------+
5 rows in set (0.00 sec)

（4）开启io_thread线程,再去查看数据库数据：
【server6】

mysql> start slave io_thread;
Query OK, 0 rows affected (0.00 sec)

mysql> start slave;
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> use test
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 * from userliat;
ERROR 1146 (42S02): Table 'test.userliat' doesn't exist
mysql> select * from userlist;
+----------+----------+
| username | password |
+----------+----------+
| user1    | 123      |
| user2    | 123      |
| user3    | 333      |
| user5    | 3333     |
| user6    | 4444     |           ##数据更新过来了
+----------+----------+
5 rows in set (0.00 sec)

mysql> show status like '%rpl_semi_sync%';     ##状态变量
+--------------------------------------------+-------+
| Variable_name                              | Value |
+--------------------------------------------+-------+
| Rpl_semi_sync_master_clients               | 1     |
| Rpl_semi_sync_master_net_avg_wait_time     | 0     |
| Rpl_semi_sync_master_net_wait_time         | 0     |
| Rpl_semi_sync_master_net_waits             | 2     |
| Rpl_semi_sync_master_no_times              | 0     |
| Rpl_semi_sync_master_no_tx                 | 0     |
| Rpl_semi_sync_master_status                | ON    |
| Rpl_semi_sync_master_timefunc_failures     | 0     |
| Rpl_semi_sync_master_tx_avg_wait_time      | 429   |
| Rpl_semi_sync_master_tx_wait_time          | 858   |
| Rpl_semi_sync_master_tx_waits              | 2     |
| Rpl_semi_sync_master_wait_pos_backtraverse | 0     |
| Rpl_semi_sync_master_wait_sessions         | 0     |
| Rpl_semi_sync_master_yes_tx                | 2     |##开启两个半同步端口
| Rpl_semi_sync_slave_status                 | ON    |
+--------------------------------------------+-------+
15 rows in set (0.01 sec)

【server7】

mysql> use test;
Database changed
mysql> select * from userlist;
+----------+----------+
| username | password |
+----------+----------+
| user1    | 123      |
| user2    | 123      |
| user3    | 333      |
| user5    | 3333     |
| user6    | 4444     |  ##数据也同步过来了
+----------+----------+
5 rows in set (0.00 sec)