mysql-MMM主主複製
MMM（Master-Master replication manager for MySQL）是一套支持雙主故障切換和雙主日常管理的腳本程序,主要管理雙主複製，而實際上在應用中只有一個主負責寫的操作，另一臺待機冗餘，或者負責讀的一部分操作。還可以結合主從複製，分離讀寫請求。
mmm分爲agent端和monitor端，agent端部署在數據庫節點上，monitor部署在監控管理端。monitor在整個數據庫集羣中是唯一存在的單點故障的點，因爲monitor端只複製監控和管理agent節點，任務量非常的輕，一般不會出現什麼故障的，而且monitor端在爲agent數據庫服務器分配完vip地址後，即使停止了monitor服務，也不會影響業務的，只需要及時的修復即可。實在不放心可以爲monitor部署keepalived.
環境
| 主機名： | 系統： | IP地址： | 安裝軟件： | 數據庫角色 |
| m1 | centos6.5 | 192.168.100.150 | mysql mysql-server mysql-mmm* | master |
| m2 | centos6.5 | 192.168.100.151 | mysql mysql-server mysql-mmm* | master |
| m3 | centos6.5 | 192.168.100.152 | mysql mysql-server mysql-mmm* | slave |
| m4 | centos6.5 | 192.168.100.153 | mysql mysql-server mysql-mmm* | slave |
| monitor | centos6.5 | 192.168.100.154 | mysql mysql-mmm* | monitor監控 |
數據庫角色，和對應vip：
| 主機： | vip | 角色 | |
| m1 | 192.168.100.250 | write | 負責寫的操作 |
| m2 | write | 平時不工作，待機冗餘 | |
| m3 | 192.168.100.201 | read | 讀的操作 |
| m4 | 192.168.100.202 | read | 讀的操作 |
修改主機名：依次修改m1 m2 m3 m4 monitor
分別在m1 - m4 安裝mysql服務：
[root@m1 ~]# yum -y install mysql mysql-server mysql-devel
[root@m2 ~]# yum -y install mysql mysql-server mysql-devel
[root@m3 ~]# yum -y install mysql mysql-server mysql-devel
[root@m4 ~]# yum -y install mysql mysql-server mysql-devel
修改m1的mysql主配置文件：
[root@m1 ~]# vi /etc/my.cnf [mysqld] datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock log-error=/var/lib/mysql/mysql.err slow_query_log_file=/var/lib/mysql/slow_query_log.log user=mysql character-set-server=utf8 log-bin=mysql-bin server-id=150 binlog-ignore-db=mysql,information_schema log-slave-updates sync_binlog=1 auto_increment_increment=2 auto_increment_offset=1 [client] default_character_set=utf8 [mysqld_safe] log-error=/var/log/mysqld.log pid-file=/var/run/mysqld/mysqld.pid
啓動mysql服務，查看是否啓動
[root@m1 ~]# /etc/init.d/mysqld start [root@m1 ~]# netstat -utpln |grep 3306 tcp 0 0 0.0.0.0:3306 0.0.0.0:* LISTEN 1359/mysqld
將mysql的主配置文件同步到m2、m3、m4服務器上
[root@m1 ~]# for i in 1 2 3;do scp /etc/my.cnf [email protected]$i:/etc/;done The authenticity of host '192.168.100.151 (192.168.100.151)' can't be established. RSA key fingerprint is 6b:3d:8b:50:dc:45:ea:58:38:6e:5d:0d:9b:8f:04:f2. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added '192.168.100.151' (RSA) to the list of known hosts. [email protected]'s password: my.cnf 100% 465 0.5KB/s 00:00 The authenticity of host '192.168.100.152 (192.168.100.152)' can't be established. RSA key fingerprint is 6b:3d:8b:50:dc:45:ea:58:38:6e:5d:0d:9b:8f:04:f2. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added '192.168.100.152' (RSA) to the list of known hosts. [email protected]'s password: my.cnf 100% 465 0.5KB/s 00:00 The authenticity of host '192.168.100.153 (192.168.100.153)' can't be established. RSA key fingerprint is 6b:3d:8b:50:dc:45:ea:58:38:6e:5d:0d:9b:8f:04:f2. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added '192.168.100.153' (RSA) to the list of known hosts. [email protected]'s password: my.cnf 100% 465 0.5KB/s 00:00
登陸數據庫查看該數據庫的bin-log文件名和偏移量：
記下File Position的信息，等會要在m1-m2-m3數據庫上用到。
[root@m1 ~]# mysqladmin -uroot password 123123 [root@m1 ~]# mysql -uroot -p123123 mysql> show master status; +------------------+----------+--------------+--------------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | +------------------+----------+--------------+--------------------------+ | mysql-bin.000003 | 249 | | mysql,information_schema | +------------------+----------+--------------+--------------------------+ 1 row in set (0.00 sec)
授權允許複製
mysql> grant replication slave on *.* to 'replication'@'192.168.100.%' identified by '123123'; Query OK, 0 rows affected (0.02 sec) ##授權replication用戶在192.168.100.0這個網段有對數據庫複製的權限 mysql> flush privileges; ##刷新權限 Query OK, 0 rows affected (0.00 sec) mysql> quit Bye
更改m2數據庫配置文件
這是m1服務器同步過來的配置文件，只需將server-id改了就可以了，server-id在mysql集羣中是唯一的標識符，在這裏以ip地址結尾定義了
[root@m2 ~]# sed -i '/server-id/s/150/151/g' /etc/my.cnf [root@m2 ~]# grep id /etc/my.cnf server-id=151 pid-file=/var/run/mysqld/mysqld.pid
啓動登入數據庫
[root@m2 ~]# /etc/init.d/mysqld start [root@m2 ~]# mysqladmin -uroot password 123123 [root@m2 ~]# mysql -uroot -p123123
在m2上查看bin-log文件和偏移量記錄下來，並授權用戶複製權限
mysql> show master status; +------------------+----------+--------------+--------------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | +------------------+----------+--------------+--------------------------+ | mysql-bin.000003 | 249 | | mysql,information_schema | +------------------+----------+--------------+--------------------------+ 1 row in set (0.00 sec) mysql> grant replication slave on *.* to 'replication'@'192.168.100.%' identified by '123123'; Query OK, 0 rows affected (0.01 sec) mysql> flush privileges; Query OK, 0 rows affected (0.05 sec)
在m1上添加另一個主m2 同步數據
[root@m1 ~]# mysql -uroot -p123123 mysql> change master to -> master_host='192.168.100.151', ##m2的ip -> master_user='replication', ##m2上面授權的用戶 -> master_password='123123', ##m2上授權用戶的密碼 -> master_log_file='mysql-bin.000003', ##m2的bin-log文件（剛剛在m2上查到的） -> master_log_pos=249; ##日誌文件的偏移量 Query OK, 0 rows affected (0.08 sec)
指定完了以後啓動同步
mysql> start slave; Query OK, 0 rows affected (0.00 sec)
查看同步狀態信息：
這兩項都爲yes算是成功了
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
mysql> show slave status\G; *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 192.168.100.151 Master_User: replication Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin.000003 Read_Master_Log_Pos: 495 Relay_Log_File: mysqld-relay-bin.000002 Relay_Log_Pos: 497 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: 495 Relay_Log_Space: 653 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: 1 row in set (0.00 sec) ERROR: No query specified
在m2上添加m2的另一個主m1：
mysql> change master to -> master_host='192.168.100.150', -> master_user='replication', -> master_password='123123', -> master_log_file='mysql-bin.000003', -> master_log_pos=249; Query OK, 0 rows affected (0.10 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: 192.168.100.150 Master_User: replication Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin.000003 Read_Master_Log_Pos: 741 Relay_Log_File: mysqld-relay-bin.000002 Relay_Log_Pos: 497 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: 741 Relay_Log_Space: 653 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: 1 row in set (0.00 sec) ERROR: No query specified
驗證：
在m1和m2上各創建個庫驗證是否同步：
m1上創建
mysql> create database m1_test; Query OK, 1 row affected (0.01 sec) mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | m1_test | | mysql | | test | | | +--------------------+ 5 rows in set (0.00 sec)
m2上查看
mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | m1_test | | mysql | | test | +--------------------+ 4 rows in set (0.07 sec)
m2上新建庫
mysql> create database test_m2; Query OK, 1 row affected (0.04 sec)
m1上查看
mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | m1_test | | mysql | | test | | test_m2 | +--------------------+ 5 rows in set (0.00 sec)
正常同步了。
在m3-m4從數據庫上指定主的數據庫
[root@m3 ~]# sed -i '/server-id/s/150/152/g' /etc/my.cnf [root@m3 ~]# grep id /etc/my.cnf server-id=152 pid-file=/var/run/mysqld/mysqld.pid [root@m3 ~]# /etc/init.d/mysqld start
[root@m3 ~]# mysqladmin -uroot password 123123 [root@m3 ~]# mysql -uroot -p123123
mysql> change master to -> master_host='192.168.100.150', -> master_user='replication', -> master_password='123123', -> master_log_file='mysql-bin.000003', -> master_log_pos=249; Query OK, 0 rows affected (0.08 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: 192.168.100.150 Master_User: replication Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin.000003 Read_Master_Log_Pos: 929 Relay_Log_File: mysqld-relay-bin.000002 Relay_Log_Pos: 931 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: 929 Relay_Log_Space: 1087 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: 1 row in set (0.04 sec) ERROR: No query specified
mysql> show databases -> ; +--------------------+ | Database | +--------------------+ | information_schema | | m1_test | | mysql | | test | | test_m2 | +--------------------+ 5 rows in set (0.08 sec) mysql>
[root@m4 ~]# sed -i '/server-id/s/150/153/g' /etc/my.cnf [root@m4 ~]# grep id /etc/my.cnf server-id=153 pid-file=/var/run/mysqld/mysqld.pid [root@m4 ~]# /etc/init.d/mysqld start [root@m4 ~]# mysqladmin -uroot password 123123 [root@m4 ~]# mysql -uroot -p123123
mysql> change master to -> master_host='192.168.100.150', -> master_user='replication', -> master_password='123123', -> master_log_file='mysql-bin.000003', -> master_log_pos=249; Query OK, 0 rows affected (0.10 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: 192.168.100.150 Master_User: replication Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin.000003 Read_Master_Log_Pos: 929 Relay_Log_File: mysqld-relay-bin.000002 Relay_Log_Pos: 931 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: 929 Relay_Log_Space: 1087 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: 1 row in set (0.00 sec) ERROR: No query specified
mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | m1_test | | mysql | | test | | test_m2 | +--------------------+ 5 rows in set (0.00 sec)
安裝mysql-mmm:
下載epel擴展yum源： 在所用服務器上執行
wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-6.repo
安裝mmm軟件： 在所有服務器上執行
yum -y install mysql-mmm*
授權： 在m1上授權，其他主機會自動同步權限
[root@m1 ~]# mysql -uroot -p123123 mysql> grant replication client on *.* to 'mmm_monitor'@'192.168.100.%' identified by 'monitor'; Query OK, 0 rows affected (0.02 sec) mysql> grant super,replication client,process on *.* to 'mmm_agent'@'192.168.100.&' identified by 'agent'; Query OK, 0 rows affected (0.00 sec) mysql> flush privileges; Query OK, 0 rows affected (0.00 sec)
修改配置文件： mmm_common.conf（所有節點的通用配置文件）
[root@monitor ~]# vi /etc/mysql-mmm/mmm_common.conf
active_master_role writer <host default> cluster_interface eth0 pid_path /var/run/mysql-mmm/mmm_agentd.pid bin_path /usr/libexec/mysql-mmm/ replication_user replication ##複製同步的用戶名 replication_password 123123 ##同步的密碼 agent_user mmm_agent ##代理的用戶名 agent_password agent ##代理密碼 </host> <host db1> ip 192.168.100.150 mode master peer db2 </host> <host db2> ip 192.168.100.151 mode master peer db1 </host> <host db3> ip 192.168.100.152 mode slave </host> <host db4> ip 192.168.100.153 mode slave </host> <role writer> hosts db1, db2 ips 192.168.100.250 ##寫的vip mode exclusive ##獨佔模式 </role> <role reader> hosts db3, db4 ips 192.168.100.201, 192.168.100.202 ##讀的vip mode balanced ##平衡模式 </role>
同步配置文件到m1 m2 m3 m4 上：
[root@monitor ~]# for i in 150 151 152 153;do scp /etc/mysql-mmm/mmm_common.conf [email protected].$i:/etc/mysql-mmm/;done The authenticity of host '192.168.100.150 (192.168.100.150)' can't be established. RSA key fingerprint is 6b:3d:8b:50:dc:45:ea:58:38:6e:5d:0d:9b:8f:04:f2. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added '192.168.100.150' (RSA) to the list of known hosts. [email protected]'s password: mmm_common.conf 100% 851 0.8KB/s 00:00 The authenticity of host '192.168.100.151 (192.168.100.151)' can't be established. RSA key fingerprint is 6b:3d:8b:50:dc:45:ea:58:38:6e:5d:0d:9b:8f:04:f2. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added '192.168.100.151' (RSA) to the list of known hosts. [email protected]'s password: mmm_common.conf 100% 851 0.8KB/s 00:00 The authenticity of host '192.168.100.152 (192.168.100.152)' can't be established. RSA key fingerprint is 6b:3d:8b:50:dc:45:ea:58:38:6e:5d:0d:9b:8f:04:f2. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added '192.168.100.152' (RSA) to the list of known hosts. [email protected]'s password: mmm_common.conf 100% 851 0.8KB/s 00:00 The authenticity of host '192.168.100.153 (192.168.100.153)' can't be established. RSA key fingerprint is 6b:3d:8b:50:dc:45:ea:58:38:6e:5d:0d:9b:8f:04:f2. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added '192.168.100.153' (RSA) to the list of known hosts. [email protected]'s password: mmm_common.conf 100% 851 0.8KB/s 00:00
修改數據庫mysql-m1到mysql-m4：
[root@m1 ~]# vi /etc/mysql-mmm/mmm_agent.conf [root@m1 ~]# cat /etc/mysql-mmm/mmm_agent.conf include mmm_common.conf this db1
[root@m2 ~]# vi /etc/mysql-mmm/mmm_agent.conf [root@m2 ~]# cat /etc/mysql-mmm/mmm_agent.conf include mmm_common.conf this db2
[root@m3 ~]# vi /etc/mysql-mmm/mmm_agent.conf [root@m3 ~]# cat /etc/mysql-mmm/mmm_agent.conf include mmm_common.conf this db3
[root@m4 ~]# vi /etc/mysql-mmm/mmm_agent.conf [root@m4 ~]# cat /etc/mysql-mmm/mmm_agent.conf include mmm_common.conf this db4
[root@monitor ~]# vi /etc/mysql-mmm/mmm_mon.conf [root@monitor ~]# cat /etc/mysql-mmm/mmm_mon.conf include mmm_common.conf <monitor> ip 127.0.0.1 pid_path /var/run/mysql-mmm/mmm_mond.pid bin_path /usr/libexec/mysql-mmm status_path /var/lib/mysql-mmm/mmm_mond.status ping_ips 192.168.100.150, 192.168.100.151, 192.168.100.152, 192.168.100.153 ##監測每個節點數據庫：修改爲每個服務器的真實ip地址 auto_set_online 60 ##自動上線時間， </monitor> <host default> monitor_user mmm_monitor ##監控服務的用戶名 monitor_password monitor ##監控服務的密碼，這兩項是在m1上授權的 </host> debug 0
啓動服務：m1-m4的mmm-agent服務; 監控端的mmm-monitor服務
[root@m1 ~]# /etc/init.d/mysql-mmm-agent start Starting MMM Agent Daemon: [確定] [root@m1 ~]#
[root@m2 ~]# [root@m2 ~]# /etc/init.d/mysql-mmm-agent start Starting MMM Agent Daemon: [確定]
[root@m3 ~]# /etc/init.d/mysql-mmm-agent start Starting MMM Agent Daemon: [確定]
[root@m4 ~]# /etc/init.d/mysql-mmm-agent start Starting MMM Agent Daemon: [確定]
[root@monitor ~]# /etc/init.d/mysql-mmm-monitor start Starting MMM Monitor Daemon: [確定]
查看各代理數據庫狀態
[root@monitor ~]# mmm_control show db1(192.168.100.150) master/ONLINE. Roles: writer(192.168.100.250) db2(192.168.100.151) master/ONLINE. Roles: db3(192.168.100.152) slave/ONLINE. Roles: reader(192.168.100.201) db4(192.168.100.153) slave/ONLINE. Roles: reader(192.168.100.202)
##發現寫的請求交給db1的vip，讀的請求交給db3 db4 vip
使用vip登錄數據庫：
先在m1上授權：因爲設置了同步，只在一個數據庫上授權，其他數據庫會同步權限
[root@m1 ~]# mysql -uroot -p123123 -s mysql> grant all on *.* to 'root'@192.168.100.154 identified by '123123'; mysql> flush privileges;
[root@monitor ~]# mysql -uroot -p123123 -h 192.168.100.250 -s mysql> show databases; Database information_schema m1_test mysql test test_m2
登陸讀的數據庫：
[root@monitor ~]# mysql -uroot -p123123 -h 192.168.100.201 -s mysql> show databases; Database information_schema m1_test mysql test test_m2 mysql>
在生產環境中，只需在應用服務器上，指定寫數據的vip地址，和讀數據的vip地址池即可。
測試：
模擬主服務器m1故障,將mysql停止了,再查看狀態：
[root@m1 ~]# /etc/init.d/mysqld stop 停止 mysqld： [確定] [root@m1 ~]#
[root@monitor ~]# mmm_control show db1(192.168.100.150) master/HARD_OFFLINE. Roles: ##顯示爲離線狀態 db2(192.168.100.151) master/ONLINE. Roles: writer(192.168.100.250) ##vip轉移到db2 db3(192.168.100.152) slave/ONLINE. Roles: reader(192.168.100.201) db4(192.168.100.153) slave/ONLINE. Roles: reader(192.168.100.202)
再把m1啓動
[root@m1 ~]# /etc/init.d/mysqld start 正在啓動 mysqld： [確定] [root@m1 ~]#
[root@monitor ~]# mmm_control show db1(192.168.100.150) master/AWAITING_RECOVERY. Roles: ##恢復狀態 db2(192.168.100.151) master/ONLINE. Roles: writer(192.168.100.250) db3(192.168.100.152) slave/ONLINE. Roles: reader(192.168.100.201) db4(192.168.100.153) slave/ONLINE. Roles: reader(192.168.100.202) [root@monitor ~]# mmm_control show db1(192.168.100.150) master/ONLINE. Roles: ##在線狀態 db2(192.168.100.151) master/ONLINE. Roles: writer(192.168.100.250) db3(192.168.100.152) slave/ONLINE. Roles: reader(192.168.100.201) db4(192.168.100.153) slave/ONLINE. Roles: reader(192.168.100.202)
模擬從數據庫m3故障，將數據庫mysql停止查看狀態，再啓動查看狀態
[root@m3 ~]# /etc/init.d/mysqld stop 停止 mysqld： [確定]
此時會將讀數據庫db3的vip轉移到db4；db4暫時負責讀的操作
[root@monitor ~]# mmm_control show db1(192.168.100.150) master/ONLINE. Roles: db2(192.168.100.151) master/ONLINE. Roles: writer(192.168.100.250) db3(192.168.100.152) slave/HARD_OFFLINE. Roles: db4(192.168.100.153) slave/ONLINE. Roles: reader(192.168.100.201), reader(192.168.100.202)
[root@m3 ~]# /etc/init.d/mysqld start 正在啓動 mysqld： [確定] [root@m3 ~]#
在db3數據庫恢復正常後，vip會轉移回來，從新工作接受讀的操作
[root@monitor ~]# mmm_control show db1(192.168.100.150) master/ONLINE. Roles: db2(192.168.100.151) master/ONLINE. Roles: writer(192.168.100.250) db3(192.168.100.152) slave/ONLINE. Roles: reader(192.168.100.201) db4(192.168.100.153) slave/ONLINE. Roles: reader(192.168.100.202)