mysql主从复制测试,【拥抱开源2】MYSQL主从复制以及切换测试
主库：192.168.1.20
从库：192.168.1.21
grant replication client,replication slave on *.* to rep@'192.168.1.21'identified by 'root';
[root@alice data]# cat /etc/my.cnf
socket=/mysql/mysql.sock
datadir=/mysql/data
socket=/mysql/mysql.sock
# Disabling symbolic-links is recommended to prevent assorted securityrisks
symbolic-links=0
default_password_lifetime=0 #密码永不过期
#skip-grant-tables
server-id=1
log-bin=mysql-bin
binlog-do-db=mysql
[mysqld_safe]
log-error=/mysql/mysqld.log
pid-file=/mysql/mysqld.pid
[root@alice log]# cat /etc/my.cnf
datadir=/mysql/data
socket=/var/lib/mysql/mysql.sock
# Disabling symbolic-links is recommended to prevent assorted securityrisks
symbolic-links=0
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
server-id=2
relay-log=relay-bin
read-only=1
change master to master_host='192.168.1.20',master_user='rep',master_password='root';
mysql> start slave;
mysql> show slave status\G;
*************************** 1. row***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.1.20
Master_User: rep
Master_Port: 3306
Connect_Retry: 60
Read_Master_Log_Pos: 339
Relay_Log_Pos: 552
Relay_Master_Log_File: mysql-bin.
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
此时应该看懂从库的slave_io_state状态正在等待主库发送事件，并且可以看到master_log_file以及开始接收主库的二进制日志mysql-bin.，证明工作正常。
反过来检查主库的同步状态：
mysql> show master status\G;
*************************** 1. row***************************
Position: 339
Binlog_Do_DB: mysql
Binlog_Ignore_DB:
Executed_Gtid_Set:
1 row in set (0.00 sec)
应该看到bin-log与position与从库的信息一致，证明数据同步点一致。
确保主从的IO-RUNNING都是yes的，此步骤在部署时已确认
mysql> show master status\G;
mysql> show slave status\G;
实际环境中，为了主库没有新数据进入，主库需要获取表锁，此时注意，FTWRL的杀伤力很大，总共有三个步骤，上全局锁，全局commit锁，清理表缓存。所以很容易将生产环境hang住。
mysql> flush tables with read lock;
Query OK, 0 rows affected (0.00 sec)
检查是否master所有的binlog已同步到slave，并且slave都已apply了所有的binlog。
mysql> show processlist;
+----+------+--------------------+-------+-------------+--------+---------------------------------------------------------------+------------------+
| Id | User | Host | db | Command | Time | State | Info |
+----+------+--------------------+-------+-------------+--------+---------------------------------------------------------------+------------------+
| 3 | rep | 192.168.1.21:36585 | NULL | Binlog Dump | | Master hassent all binlog to slave; waiting for more updates | NULL |
| 6 | root | localhost | mysql | Query | 0 | starting | show processlist |
+----+------+--------------------+-------+-------------+--------+---------------------------------------------------------------+------------------+
2 rows in set (0.00 sec)
mysql> mysql> show processlist;
+----+-------------+-----------+------+---------+--------+--------------------------------------------------------+------------------+
| Id | User | Host | db | Command | Time | State | Info |
+----+-------------+-----------+------+---------+--------+--------------------------------------------------------+------------------+
| 6 | system user | | NULL | Connect | | Waiting for master to sendevent | NULL |
| 7 | system user | | NULL | Connect | | Slave has read all relaylog; waiting for more updates | NULL |
| 8 | root | localhost | NULL | Query | 0 | starting | show processlist |
+----+-------------+-----------+------+---------+--------+--------------------------------------------------------+------------------+
3 rows in set (0.00 sec)
看到Master has sent all binlog to slave; waiting for more updates与Slave has read all relay log; waiting for more updates，代表同步已经完成，没有正在进行中的进程活动。
mysql> stop slave io_thread;
Query OK, 0 rows affected (0.00 sec)
--修改新主库192.168.1.21的配置文件
[root@alice log]# cat /etc/my.cnf
datadir=/mysql/data
socket=/var/lib/mysql/mysql.sock
# Disabling symbolic-links is recommended to prevent assorted securityrisks
symbolic-links=0
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
server-id=1
#relay-log=relay-bin
log-bin=mysql-bin
binlog-do-db=mysql
read-only=0
##关闭中继日志应用，开始二进制应用，关闭只读模式
[root@alice log]# service mysqld restart
Stopping mysqld: [ OK ]
Starting mysqld: [ OK ]
mysql> stop slave
Query OK, 0 rows affected, 1 warning (0.00 sec)
mysql> reset master;
Query OK, 0 rows affected (0.01 sec)
mysql> reset slave all;
Query OK, 0 rows affected (0.01 sec)
mysql> show variables like 'read_only';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| read_only | OFF |
+---------------+-------+
1 row in set (0.02 sec)
mysql> show master status\G;
*************************** 1. row ***************************
Position: 154
Binlog_Do_DB: mysql
Binlog_Ignore_DB:
Executed_Gtid_Set:
1 row in set (0.00 sec)
No query specified
grant replication client,replication slave on *.* to rep@'192.168.1.20'identified by 'root';
到此新主库的切换完成。
[root@alice data]# cat /etc/my.cnf
socket=/mysql/mysql.sock
datadir=/mysql/data
socket=/mysql/mysql.sock
# Disabling symbolic-links is recommended to prevent assorted securityrisks
symbolic-links=0
#skip-grant-tables
server-id=2
#log-bin=mysql-bin
#binlog-do-db=mysql
relay-log=relay-bin
read-only=1
[mysqld_safe]
log-error=/mysql/mysqld.log
pid-file=/mysql/mysqld.pid
[root@alice data]# service mysqld restart
Shutting down MySQL.. [ OK ]
Starting MySQL. [ OK ]
mysql> reset master;
Query OK, 0 rows affected (0.00 sec)
mysql> change master tomaster_host='192.168.1.21',master_user='rep',master_password='root';
Query OK, 0 rows affected, 2 warnings (0.03 sec)
mysql> start slave;
Query OK, 0 rows affected (0.00 sec)
mysql> show slave status\G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.1.21
Master_User: rep
Master_Port: 3306
Connect_Retry: 60
Read_Master_Log_Pos: 467
Relay_Log_Pos: 680
Relay_Master_Log_File: mysql-bin.
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
到此新从库切换完成。