雙主雙從
一個主機 m1 用於處理所有寫請求，它的從機 s1 和另一台主機 m2 還有它的從機 s2 負責所有讀請
求。當 m1 主機宕機后，m2 主機負責寫請求，m1、m2 互為備機。
角色 地址
master1 192.168.199.231
slave1 192.168.199.185
master2 192.168.199.120
slave2 192.168.199.174
注意：在一主一從基本上需要刪除testdb以及恢復從機
mater1配置
修改/etc/my.cnf文件
#主服務器唯一ID server-id=1 ##啟用二進制日志 log-bin=mysql-bin ## 設置不要復制的數據庫(可設置多個) binlog-ignore-db=mysql ##binlog-ignore-db=information_schema ##設置需要復制的數據庫 binlog-do-db=testdb ##設置logbin格式 binlog_format=STATEMENT
新加配置
# 在作為從數據庫的時候，有寫入操作也要更新二進制日志文件 log-slave-updates #表示自增長字段每次遞增的量，指自增字段的起始值，其默認值是1，取值范圍是1 .. 65535 auto-increment-increment=2 ## 表示自增長字段從哪個數開始，指字段一次遞增多少，他的取值范圍是1 .. 65535 auto-increment-offset=1
master2配置
/etc/my.cnf
#主服務器唯一ID server-id=3 #啟用二進制日志 log-bin=mysql-bin # 設置不要復制的數據庫(可設置多個) binlog-ignore-db=mysql binlog-ignore-db=information_schema #設置需要復制的數據庫 binlog-do-db=testdb ##設置logbin格式 binlog_format=STATEMENT ## 在作為從數據庫的時候，有寫入操作也要更新二進制日志文件 log-slave-updates ##表示自增長字段每次遞增的量，指自增字段的起始值，其默認值是1，取值范圍是1 .. 65535 auto-increment-increment=2 ## 表示自增長字段從哪個數開始，指字段一次遞增多少，他的取值范圍是1 .. 65535 auto-increment-offset=2
slave1配置
#從服務器唯一ID server-id=2 ##啟用中繼日志 relay-log=mysql-relay
slave2配置
#從服務器唯一ID server-id=4
#啟用中繼日志 relay-log=mysql-relay
①、配置好哦之后進行mysql服務的重啟
②、關閉防火牆
③、 在兩台主機上建立帳戶並授權 slave
#在主機MySQL里執行授權命令 GRANT REPLICATION SLAVE ON *.* TO 'slave'@'%' IDENTIFIED BY '123123';
查看主機master1狀態
mysql> show master status -> ; +------------------+----------+--------------+------------------+-------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set | +------------------+----------+--------------+------------------+-------------------+ | mysql-bin.000010 | 120 | testdb | mysql | | +------------------+----------+--------------+------------------+-------------------+ 1 row in set (0.00 sec)
查詢
Master2的狀態
mysql> show master status -> ; +------------------+----------+--------------+--------------------------+-------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set | +------------------+----------+--------------+--------------------------+-------------------+ | mysql-bin.000002 | 120 | testdb | mysql,information_schema | | +------------------+----------+--------------+--------------------------+-------------------+ 1 row in set (0.00 sec)
#分別記錄下File和Position的值
#執行完此步驟后不要再操作主服務器MYSQL，防止主服務器狀態值變化
在兩台主機創建slave
GRANT REPLICATION SLAVE ON *.* TO 'slave'@'%' IDENTIFIED BY '123123';
④、在從機上配置需要復制的主機
slave1·
mysql> CHANGE MASTER TO MASTER_HOST='192.168.199.231', -> MASTER_USER='slave', -> MASTER_PASSWORD='123123', -> MASTER_LOG_FILE='mysql-bin.000010',MASTER_LOG_POS=120; Query OK, 0 rows affected, 2 warnings (0.01 sec) mysql> start slave; Query OK, 0 rows affected (0.01 sec)
slave2
mysql> CHANGE MASTER TO MASTER_HOST='192.168.199.120',
-> MASTER_USER='slave',
-> MASTER_PASSWORD='123123',
-> MASTER_LOG_FILE='mysql-bin.000002',MASTER_LOG_POS=120;
Query OK, 0 rows affected, 2 warnings (0.03 sec)
mysql> start slave;
Query OK, 0 rows affected (0.00 sec)
此時master1和slave1，master2和slave2的主從復制搭建完成
⑤、兩個主機互相復制
master1和master2互備主從賦值
master1執行（即連接master2的主機IP地址）
mysql> CHANGE MASTER TO MASTER_HOST='192.168.199.120',
-> MASTER_USER='slave',
-> MASTER_PASSWORD='123123',
-> MASTER_LOG_FILE='mysql-bin.000002',MASTER_LOG_POS=120;
Query OK, 0 rows affected, 2 warnings (0.05 sec)
mysql> start slave;
Query OK, 0 rows affected (0.00 sec)
master2執行（即連接master1的主機IP地址）
mysql> CHANGE MASTER TO MASTER_HOST='192.168.199.231', -> MASTER_USER='slave', -> MASTER_PASSWORD='123123', -> MASTER_LOG_FILE='mysql-bin.000010',MASTER_LOG_POS=120; Query OK, 0 rows affected, 2 warnings (0.07 sec) mysql> start slave; Query OK, 0 rows affected (0.00 sec)
⑥、 Master1 主機新建庫、新建表、insert 記錄，Master2 和從機復制
創建數據庫
master1
mysql> create database testdb; Query OK, 1 row affected (0.00 sec) mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | metastore | | mysql | | performance_schema | | test | | testdb | +--------------------+ 6 rows in set (0.00 sec)
slave2
mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | metastore | | mysql | | performance_schema | | test | | testdb | +--------------------+ 6 rows in set (0.00 sec)
master2
mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | metastore | | mysql | | performance_schema | | test | | testdb | +--------------------+ 6 rows in set (0.01 sec)
slave2
mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | metastore | | mysql | | performance_schema | | test | | testdb | +--------------------+ 6 rows in set (0.00 sec)
創建表以及插入數據
master1
mysql> use testdb; Database changed
mysql> create table tbl(id int,name varchar(40)); Query OK, 0 rows affected (0.03 sec) mysql> insert into tbl values (1,'mrchengs'); Query OK, 1 row affected (0.00 sec)
slave1
mysql> use testdb; 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 tbl; +------+----------+ | id | name | +------+----------+ | 1 | mrchengs | +------+----------+ 1 row in set (0.00 sec)
master2
mysql> use testdb; 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 tbl; +------+----------+ | id | name | +------+----------+ | 1 | mrchengs | +------+----------+ 1 row in set (0.00 sec)
slave2
mysql> use testdb; 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 tbl; +------+----------+ | id | name | +------+----------+ | 1 | mrchengs | +------+----------+ 1 row in set (0.00 sec)
mycat的使用
①、修改schema.xml配置文件
配置項說明
#balance="1": 全部的readHost與stand by writeHost參與select語句的負載均衡。
#
writeType="0": 所有寫操作發送到配置的第一個writeHost，
第一個掛了切到還生存的第二個
#
writeType="1"，所有寫操作都隨機的發送到配置的 writeHost，1.5 以后廢棄不推薦
#
writeHost，重新啟動后以切換后的為准，切換記錄在配置文件中:dnindex.properties 。
#
switchType=
1 : 1 默認值，自動切換。
-1 表示不自動切換
2 基於 MySQL 主從同步的狀態決定是否切換。
②、啟動mycat
③、驗證讀寫分離
在master1上執行插入語句
INSERT INTO mytbl VALUES(3,@@hostname);
mysql> select * from tbl; +------+-----------------------+ | id | name | +------+-----------------------+ | 1 | mrchengs | | 3 | localhost.localdomain | +------+-----------------------+ 2 rows in set (0.01 sec)
slave2
mysql> select * from tbl; +------+----------+ | id | name | +------+----------+ | 1 | mrchengs | | 3 | mycat03 | +------+----------+ 2 rows in set (0.00 sec)
master2
mysql> select * from tbl; +------+----------+ | id | name | +------+----------+ | 1 | mrchengs | | 3 | mycat04 | +------+----------+ 2 rows in set (0.00 sec)
slave2
mysql> select * from tbl; +------+----------+ | id | name | +------+----------+ | 1 | mrchengs | | 3 | mycat05 | +------+----------+ 2 rows in set (0.00 sec)
④、登陸mycat
[root@localhost ~]# mysql -umycat -p123456 -P 8066 -h 192.168.199.217
進行驗證讀寫分離
mysql> select * from tbl; +------+----------+ | id | name | +------+----------+ | 1 | mrchengs | | 3 | mycat04 | +------+----------+ 2 rows in set (0.00 sec) mysql> select * from tbl; +------+----------+ | id | name | +------+----------+ | 1 | mrchengs | | 3 | mycat03 | +------+----------+ 2 rows in set (0.00 sec) mysql> select * from tbl; +------+----------+ | id | name | +------+----------+ | 1 | mrchengs | | 3 | mycat05 | +------+----------+ 2 rows in set (0.07 sec)
⑤、
高可用下的抗風險能力（高可用）
關閉master1查詢在配置文件中配置是否進行切換寫主機數據庫
[root@localhost ~]# systemctl stop mysql [root@localhost ~]# systemctl status mysql ● mysql.service - LSB: start and stop MySQL Loaded: loaded (/etc/rc.d/init.d/mysql; bad; vendor preset: disabled) Active: inactive (dead) since Thu 2020-02-13 20:15:06 CST; 8s ago Docs: man:systemd-sysv-generator(8) Process: 1632 ExecStop=/etc/rc.d/init.d/mysql stop (code=exited, status=0/SUCCESS) Process: 1070 ExecStart=/etc/rc.d/init.d/mysql start (code=exited, status=0/SUCCESS) Feb 13 19:18:32 localhost.localdomain systemd[1]: Starting LSB: start and stop MySQL... Feb 13 19:18:33 localhost.localdomain mysql[1070]: Starting MySQL SUCCESS! Feb 13 19:18:33 localhost.localdomain systemd[1]: Started LSB: start and stop MySQL. Feb 13 20:14:50 localhost.localdomain systemd[1]: Stopping LSB: start and stop MySQL... Feb 13 20:15:06 localhost.localdomain mysql[1632]: Shutting down MySQL.............. SUCCESS! Feb 13 20:15:06 localhost.localdomain systemd[1]: Stopped LSB: start and stop MySQL.
mycat客戶端中執行插入代碼
mysql> INSERT INTO tbl VALUES(100,@@hostname); Query OK, 1 row affected, 1 warning (0.15 sec)
啟動master1進行查看數據、
mysql> select * from tbl; +------+-----------------------+ | id | name | +------+-----------------------+ | 1 | mrchengs | | 3 | localhost.localdomain | | 100 | localhost.localdomain | +------+-----------------------+ 3 rows in set (0.00 sec)
在mycat上進行查詢
mysql> select * from tbl; +------+----------+ | id | name | +------+----------+ | 1 | mrchengs | | 3 | mycat05 | | 100 | mycat05 | +------+----------+ 3 rows in set (0.00 sec) mysql> select * from tbl; +------+-----------------------+ | id | name | +------+-----------------------+ | 1 | mrchengs | | 3 | localhost.localdomain | | 100 | localhost.localdomain | +------+-----------------------+ 3 rows in set (0.00 sec) mysql> select * from tbl; +------+----------+ | id | name | +------+----------+ | 1 | mrchengs | | 3 | mycat03 | | 100 | mycat03 | +------+----------+ 3 rows in set (0.00 sec)
此時master1成為讀主機
此時master2成為寫主機