Mysql主从---删除master.info和relya-log.info实验

relay-log.info, master.info 这连个文件时在建立复制时产生的，现在主要说明以下问题:

1、如果修改删除master.info文件，复制会中断么?

不会,如果stop slave,然后start slave还是能正常启动起来，因为MySQL已经记住这里面的信息了，

但是当你重启mysql时，在start slave,这时重启失败，会提示你change master to

测试如下

这里我的主从环境是级联的，结构如下

master-->slave1-->slave2

 data-1-1机器安装两个实例，一个是master（3306端口），一个是slave2（3307端口）

 data-1-2机器安装一个实例，3306端口，作为slave1

结构图如下

两台机器的环境

#data-1-1机器
[root@data-1-1 ~]# ifconfig eth0 | grep "inet addr"
          inet addr:10.0.1.81  Bcast:10.0.1.255  Mask:255.255.255.0
[root@data-1-1 ~]# uname -mrm
2.6.32-504.el6.x86_64 x86_64
[root@data-1-1 ~]# cat /etc/redhat-release 
CentOS release 6.6 (Final)
[root@data-1-1 ~]#  mysql -uroot -poldboy123  -S  /data/3307/mysql.sock  -e   "select version();"
+------------+
| version()  |
+------------+
| 5.5.32-log |
+------------+
[root@data-1-1 ~]# 
#mysql路径
#master
#/data/3306/
#slave2路径
#/data/3307/

#data-1-2机器
[root@data-1-2 ~]# ifconfig eth0 | grep "inet addr"
          inet addr:10.0.1.82  Bcast:10.0.1.255  Mask:255.255.255.0
[root@data-1-2 ~]# uname -rm
2.6.32-504.el6.x86_64 x86_64
[root@data-1-2 ~]# cat /etc/redhat-release 
CentOS release 6.6 (Final)
#mysql路径 
[root@data-1-2 ~]# ll /application/mysql/

删除slave2的master.info

[root@data-1-1 ~]# mv /data/3307/data/master.info master.info.bak 
[root@data-1-1 ~]# cat master.info.bak 
18
mysql-bin.000004
2448
10.0.1.82
rep
oldboy123
3306
60
0





0
1800.000

0
[root@data-1-1 ~]# 

不重启slave2的mysq服务，主从不受影响，停止slave和启动slave后也主从是不受影响的

[root@data-1-1 ~]#  mysql -uroot -poldboy123  -S  /data/3306/mysql.sock  -e   "create database d18;"
[root@data-1-1 ~]#  mysql -uroot -poldboy123  -S  /data/3307/mysql.sock  -e   "show databases;"
+--------------------+
| Database           |
+--------------------+
| information_schema |
| d18                |
| dd5                |
| mysql              |
| performance_schema |
| t1                 |
| test               |
+--------------------+
[root@data-1-1 ~]#  mysql -uroot -poldboy123  -S  /data/3307/mysql.sock  -e   "stop slave;"
[root@data-1-1 ~]#  mysql -uroot -poldboy123  -S  /data/3307/mysql.sock  -e   "start slave;"
[root@data-1-1 ~]#  mysql -uroot -poldboy123  -S  /data/3306/mysql.sock  -e   "create database d19;"
[root@data-1-1 ~]#  mysql -uroot -poldboy123  -S  /data/3307/mysql.sock  -e   "show databases;"
+--------------------+
| Database           |
+--------------------+
| information_schema |
| d18                |
| d19                |
| dd5                |
| mysql              |
| performance_schema |
| t1                 |
| test               |
+--------------------+
[root@data-1-1 ~]# 

重启slave2的mysql服务，再观察主从，出现报错提示change matser  to

[root@data-1-1 ~]# /data/3307/mysql stop
Stoping MySQL...
[root@data-1-1 ~]# /data/3307/mysql start
Starting MySQL...
[root@data-1-1 ~]#  mysql -uroot -poldboy123  -S  /data/3307/mysql.sock  -e   "show slave statusG;"
[root@data-1-1 ~]#  mysql -uroot -poldboy123  -S  /data/3307/mysql.sock  -e   "start slave;"
ERROR 1200 (HY000) at line 1: The server is not configured as slave; fix in config file or with CHANGE MASTER TO

在slave1上取位置点，也就是说再slave2的master上取位置点

先让日志滚动一下

下面的操作为了取位置点

[root@data-1-1 ~]#  mysql -uroot -poldboy123  -S  /data/3306/mysql.sock  -e   "create database d20;"
[root@data-1-1 ~]# 

slave1上取位置点

[root@data-1-2 ~]# mysqlbinlog /application/mysql/data/mysql-bin.000004 >bin4.log
[root@data-1-2 ~]# tail -15 bin4.log 
# at 2529
#170118 17:31:51 server id 1  end_log_pos 2610 	Query	thread_id=185	exec_time=18	error_code=0
SET TIMESTAMP=1484731911/*!*/;
create database d19
/*!*/;
# at 2610
#170118 17:54:31 server id 1  end_log_pos 2691 	Query	thread_id=186	exec_time=17	error_code=0
SET TIMESTAMP=1484733271/*!*/;
create database d20
/*!*/;
DELIMITER ;
# End of log file
ROLLBACK /* added by mysqlbinlog */;
/*!50003 SET COMPLETION_TYPE=@OLD_COMPLETION_TYPE*/;
/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=0*/;
[root@data-1-2 ~]# 

salve2重新做主从

CHANGE  MASTER TO
MASTER_HOST='10.0.1.82',
MASTER_PORT=3306,
MASTER_USER='rep',
MASTER_PASSWORD='oldboy123',
MASTER_LOG_FILE='mysql-bin.000004',
MASTER_LOG_POS=2610;

执行如下

[root@data-1-1 ~]# mysql -uroot -poldboy123  -S  /data/3307/mysql.sock  -e   "CHANGE  MASTER TO MASTER_HOST='10.0.1.82',MASTER_PORT=3306,MASTER_USER='rep',MASTER_PASSWORD='oldboy123',MASTER_LOG_FILE='mysql-bin.000004',MASTER_LOG_POS=2610;"
[root@data-1-1 ~]#  mysql -uroot -poldboy123  -S  /data/3307/mysql.sock  -e   "start slave;"
[root@data-1-1 ~]#  mysql -uroot -poldboy123  -S  /data/3307/mysql.sock  -e   "show slave statusG;"
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 10.0.1.82
                  Master_User: rep
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000004
          Read_Master_Log_Pos: 2691
               Relay_Log_File: relay-bin.000002
                Relay_Log_Pos: 334
        Relay_Master_Log_File: mysql-bin.000004
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
              Replicate_Do_DB: 
          Replicate_Ignore_DB: mysql
           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: 2691
              Relay_Log_Space: 484
              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: 12
[root@data-1-1 ~]#  mysql -uroot -poldboy123  -S  /data/3306/mysql.sock  -e   "create database d21;"
[root@data-1-1 ~]#  mysql -uroot -poldboy123  -S  /data/3307/mysql.sock  -e   "show databases;"
+--------------------+
| Database           |
+--------------------+
| information_schema |
| d18                |
| d19                |
| d20                |
| d21                |
| dd5                |
| mysql              |
| performance_schema |
| t1                 |
| test               |
+--------------------+
[root@data-1-1 ~]# 

2、master.info是在什么时候写入的呢？

change master to ..

经过我的测试，它的位置信息会变化的。

[root@data-1-1 ~]# cat /data/3307/data/master.info 
18
mysql-bin.000004
2772
10.0.1.82
rep
oldboy123
3306
60
0





0
1800.000

0
[root@data-1-1 ~]# 

3.关于relay-log.info

删除relay-log.info之后，stop slave和start  slave，主从依然正常

[root@data-1-1 ~]# mv /data/3307/relay-log.info relya-log.info.bak
[root@data-1-1 ~]#  mysql -uroot -poldboy123  -S  /data/3306/mysql.sock  -e   "create database d22;"
[root@data-1-1 ~]#  mysql -uroot -poldboy123  -S  /data/3307/mysql.sock  -e   "show databases;" | grep d22
d22
[root@data-1-1 ~]#  mysql -uroot -poldboy123  -S  /data/3307/mysql.sock  -e   "show databases;" 
+--------------------+
| Database           |
+--------------------+
| information_schema |
| d18                |
| d19                |
| d20                |
| d21                |
| d22                |
| dd5                |
| mysql              |
| performance_schema |
| t1                 |
| test               |
+--------------------+
[root@data-1-1 ~]#  mysql -uroot -poldboy123  -S  /data/3307/mysql.sock  -e   "stop slave;"
[root@data-1-1 ~]#  mysql -uroot -poldboy123  -S  /data/3307/mysql.sock  -e   "start slave;"
[root@data-1-1 ~]#  mysql -uroot -poldboy123  -S  /data/3306/mysql.sock  -e   "create database d23;"
[root@data-1-1 ~]#  mysql -uroot -poldboy123  -S  /data/3307/mysql.sock  -e   "show databases;" 
+--------------------+
| Database           |
+--------------------+
| information_schema |
| d18                |
| d19                |
| d20                |
| d21                |
| d22                |
| d23                |
| dd5                |
| mysql              |
| performance_schema |
| t1                 |
| test               |
+--------------------+
[root@data-1-1 ~]# 

重启mysql服务后，主从同步报错

[root@data-1-1 ~]# /data/3307/mysql stop
Stoping MySQL...
[root@data-1-1 ~]# lsof -i:3307
[root@data-1-1 ~]# /data/3307/mysql start
Starting MySQL...
[root@data-1-1 ~]# lsof -i:3307
[root@data-1-1 ~]# lsof -i:3307
COMMAND   PID  USER   FD   TYPE  DEVICE SIZE/OFF NODE NAME
mysqld  94497 mysql   12u  IPv4 1003041      0t0  TCP *:opsession-prxy (LISTEN)
[root@data-1-1 ~]#  mysql -uroot -poldboy123  -S  /data/3307/mysql.sock  -e   "show slave statusG;"
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 10.0.1.82
                  Master_User: rep
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000004
          Read_Master_Log_Pos: 2934
               Relay_Log_File: relay-bin.000002
                Relay_Log_Pos: 253
        Relay_Master_Log_File: mysql-bin.000004
             Slave_IO_Running: Yes
            Slave_SQL_Running: No
              Replicate_Do_DB: 
          Replicate_Ignore_DB: mysql
           Replicate_Do_Table: 
       Replicate_Ignore_Table: 
      Replicate_Wild_Do_Table: 
  Replicate_Wild_Ignore_Table: 
                   Last_Errno: 1007
                   Last_Error: Error 'Can't create database 'd20'; database exists' on query. Default database: 'd20'. Query: 'create database d20'
                 Skip_Counter: 0
          Exec_Master_Log_Pos: 2610
              Relay_Log_Space: 1295
              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 'd20'; database exists' on query. Default database: 'd20'. Query: 'create database d20'
  Replicate_Ignore_Server_Ids: 
             Master_Server_Id: 12
[root@data-1-1 ~]# 

处理如下，跳过错误即可

stop slave; 
set global sql_slave_skip_counter=1; （1是指跳过一个错误）
slave start;　　

处理如下

[root@data-1-1 ~]#  mysql -uroot -poldboy123  -S  /data/3307/mysql.sock  -e   "stop slave;"
[root@data-1-1 ~]#  mysql -uroot -poldboy123  -S  /data/3307/mysql.sock  -e   "set global sql_slave_skip_counter=1;"
[root@data-1-1 ~]#  mysql -uroot -poldboy123  -S  /data/3307/mysql.sock  -e   "start slave;"
[root@data-1-1 ~]#  mysql -uroot -poldboy123  -S  /data/3307/mysql.sock  -e   "show slave statusG;"
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 10.0.1.82
                  Master_User: rep
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000004
          Read_Master_Log_Pos: 2934
               Relay_Log_File: relay-bin.000002
                Relay_Log_Pos: 334
        Relay_Master_Log_File: mysql-bin.000004
             Slave_IO_Running: Yes
            Slave_SQL_Running: No
              Replicate_Do_DB: 
          Replicate_Ignore_DB: mysql
           Replicate_Do_Table: 
       Replicate_Ignore_Table: 
      Replicate_Wild_Do_Table: 
  Replicate_Wild_Ignore_Table: 
                   Last_Errno: 1007
                   Last_Error: Error 'Can't create database 'd21'; database exists' on query. Default database: 'd21'. Query: 'create database d21'
                 Skip_Counter: 0
          Exec_Master_Log_Pos: 2691
              Relay_Log_Space: 1591
              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 'd21'; database exists' on query. Default database: 'd21'. Query: 'create database d21'
  Replicate_Ignore_Server_Ids: 
             Master_Server_Id: 12
[root@data-1-1 ~]#  mysql -uroot -poldboy123  -S  /data/3307/mysql.sock  -e   "stop slave;"
[root@data-1-1 ~]#  mysql -uroot -poldboy123  -S  /data/3307/mysql.sock  -e   "set global sql_slave_skip_counter=3;"
[root@data-1-1 ~]#  mysql -uroot -poldboy123  -S  /data/3307/mysql.sock  -e   "start slave;"
[root@data-1-1 ~]#  mysql -uroot -poldboy123  -S  /data/3307/mysql.sock  -e   "show slave statusG;"
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 10.0.1.82
                  Master_User: rep
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000004
          Read_Master_Log_Pos: 2934
               Relay_Log_File: relay-bin.000007
                Relay_Log_Pos: 253
        Relay_Master_Log_File: mysql-bin.000004
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
              Replicate_Do_DB: 
          Replicate_Ignore_DB: mysql
           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: 2934
              Relay_Log_Space: 549
              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: 12
[root@data-1-1 ~]#