目录
1.mysql简介
在现代企业中,数据显得尤为重要,而存储数据的数据库选择又五花八门,但无论是何种数据库,均存在着一种隐患。
想几个问题:
- 用一台数据库存放数据,若此数据库服务器宕机了导致数据丢失怎么办?
- 业务量大了,数据多了,访问的人多了,一台数据库无法保证服务质量了怎么办?
1.1 主从作用
- 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(这里的备份不是指数据库的备份,而是服务器的备份,相当于一台备用服务器)
1.2 主从形式
- 一主一从
- 主主复制
- 一主多从---扩展系统读取的性能,因为读是在从库读取的
- 多主一从---5.7开始支持
联级复制
2. 主从复制原理
主从复制步骤:- 主库将所有的写操作记录到binlog日志中并生成一个log dump线程,将binlog日志传给从库的I/O线程
- 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,并将得到的binlog日志写到relay log(中继日志) 文件中
SQL线程,会读取relay log文件中的日志,并解析成具体操作,来实现主从的操作一致,达到最终数据一致的目的
3. 主从复制配置
主从复制配置步骤:
1.确保从数据库与主数据库里的数据一样
2.在主数据库里创建一个同步账号授权给从数据库使用
3.配置主数据库(修改配置文件)
4.配置从数据库(修改配置文件)
需求:
搭建两台MySQL服务器,一台作为主服务器,一台作为从服务器,主服务器进行写操作,从服务器进行读操作
环境说明:
数据库角色 | IP | 应用与系统版本 | 有无数据 |
---|---|---|---|
主数据库 | 192.168.153.152 | centos7/redhat7 mysql-5.7 |
无数据到有数据 |
从数据库 | 192.168.153.162 | centos7/redhat7 mysql-5.7 |
无数据 |
从数据库 | 192.168.153.164 | centos7/redhat7 mysql-5.7 |
无数据 |
3.1 mysql安装
[root@localhost ~]# groupadd -r -g 306 mysql [root@localhost ~]# useradd -M -s /sbin/nologin -g 306 -u 306 mysql [root@localhost ~]# tar xf mysql-5.7.22-linux-glibc2.12-x86_64.tar.gz -C /usr/local/ [root@localhost ~]# cd /usr/local/ [root@localhost local]# ln -sv mysql-5.7.22-linux-glibc2.12-x86_64 mysql "mysql" -> "mysql-5.7.22-linux-glibc2.12-x86_64" [root@localhost local]# chown -R mysql.mysql /usr/local/mysql* [root@localhost local]# ll /usr/local/mysql -d lrwxrwxrwx. 1 mysql mysql 35 5月 15 23:26 /usr/local/mysql -> mysql-5.7.22-linux-glibc2.12-x86_64 [root@localhost local]# ls bin games lib libexec mysql-5.7.22-linux-glibc2.12-x86_64 share etc include lib64 mysql sbin src [root@localhost local]# cd [root@localhost ~]# echo 'export PATH=/usr/local/mysql/bin:$PATH' > /etc/profile.d/mysql.sh [root@localhost ~]# . /etc/profile.d/mysql.sh [root@localhost ~]# mkdir /opt/data [root@localhost ~]# chown -R mysql.mysql /opt/data/ [root@localhost ~]# /usr/local/mysql/bin/mysqld --initialize --user=mysql --datadir=/opt/data/ 2019-05-15T15:33:17.059360Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details). 2019-05-15T15:33:17.309490Z 0 [Warning] InnoDB: New log files created, LSN=45790 2019-05-15T15:33:17.634883Z 0 [Warning] InnoDB: Creating foreign key constraint system tables. 2019-05-15T15:33:17.910710Z 0 [Warning] No existing UUID has been found, so we assume that this is the first time that this server has been started. Generating a new UUID: c33692ba-7726-11e9-8825-000c29c97322. 2019-05-15T15:33:17.911242Z 0 [Warning] Gtid table is not ready to be used. Table 'mysql.gtid_executed' cannot be opened. 2019-05-15T15:33:17.911859Z 1 [Note] A temporary password is generated for root@localhost: %l.lUhAhl4;n [root@localhost ~]# echo '%l.lUhAhl4;n' > pass [root@localhost ~]# cp -a /usr/local/mysql/support-files/mysql.server /etc/init.d/mysqld [root@localhost ~]# cp -a /usr/local/mysql/support-files/mysql.server /etc/init.d/mysqld [root@localhost ~]# sed -ri 's#^(basedir=).*#\1/usr/local/mysql#g' /etc/init.d/mysqld [root@localhost ~]# sed -ri 's#^(datadir=).*#\1/opt/data#g' /etc/init.d/mysqld [root@localhost ~]# /etc/init.d/mysqld start Starting MySQL.Logging to '/opt/data/localhost.localdomain.err'. SUCCESS! [root@localhost ~]# ss -antl State Recv-Q Send-Q Local Address:Port Peer Address:Port LISTEN 0 128 *:22 *:* LISTEN 0 100 127.0.0.1:25 *:* LISTEN 0 128 :::22 :::* LISTEN 0 100 ::1:25 :::* LISTEN 0 80 :::3306 :::*
3.2 mysql主从配置
3.2.1 确保从数据库与主数据库里的数据一样(两个里面都无数据)
3.2.2 在主数据库里创建一个同步账号授权给从数据库使用
mysql> set password=password('ly123'); Query OK, 0 rows affected, 1 warning (0.00 sec) mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | | sys | +--------------------+ 4 rows in set (0.00 sec) mysql> create user 'repl'@'192.168.153.162' identified by 'repl123'; Query OK, 0 rows affected (0.00 sec) mysql> GRANT REPLICATION SLAVE ON *.* TO 'repl'@'192.168.153.162'; Query OK, 0 rows affected (0.00 sec) mysql> flush privileges; Query OK, 0 rows affected (0.00 sec) mysql> quit
3.2.3 配置主数据库
[root@localhost ~]# vim /etc/my.cnf //在[mysqld]这段的后面加上如下内容 [mysqld] datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock log-bin=mysql-bin //启用binlog日志 server-id=1 //数据库服务器唯一标识符,主库的server-id值必须比从库的小 symbolic-links=0 log-error=/var/log/mysqld.log pid-file=/var/run/mysqld/mysqld.pid //重启mysql服务 [root@localhost ~]# /etc/init.d/mysqld restart Shutting down MySQL.. SUCCESS! Starting MySQL. SUCCESS! [root@localhost ~]# ss -antl State Recv-Q Send-Q Local Address:Port Peer Address:Port LISTEN 0 128 *:22 *:* LISTEN 0 100 127.0.0.1:25 *:* LISTEN 0 128 :::22 :::* LISTEN 0 100 ::1:25 :::* LISTEN 0 80 :::3306 :::* //查看主库的状态 [root@localhost ~]# mysql -uroot -ply123 mysql: [Warning] Using a password on the command line interface can be insecure. Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 2 Server version: 5.7.22-log MySQL Community Server (GPL) Copyright (c) 2000, 2018, 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 master status; +------------------+----------+--------------+------------------+-------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set | +------------------+----------+--------------+------------------+-------------------+ | mysql-bin.000001 | 154 | | | | +------------------+----------+--------------+------------------+-------------------+ 1 row in set (0.00 sec)
3.2.4 配置从数据库
[root@localhost ~]# vim /etc/my.cnf //添加如下内容 [mysqld] datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock server-id=2 //设置从库的唯一标识符,从库的server-id值必须大于主库的该值 relay-log=mysql-relay-bin //启用中继日志relay-log symbolic-links=0 log-error=/var/log/mysqld.log pid-file=/var/run/mysqld/mysqld.pid //重启从库的mysql服务 [root@localhost ~]# /etc/init.d/mysqld restart Shutting down MySQL.. SUCCESS! Starting MySQL. SUCCESS! [root@localhost ~]# ss -antl State Recv-Q Send-Q Local Address:Port Peer Address:Port LISTEN 0 128 *:22 *:* LISTEN 0 100 127.0.0.1:25 *:* LISTEN 0 128 :::22 :::* LISTEN 0 100 ::1:25 :::* LISTEN 0 80 :::3306 :::* //配置并启动主从复制 mysql> change master to master_host='192.168.153.152',master_user='repl',mastter_password='repl123',master_log_file='mysql-bin.000001',master_log_pos=154;; Query OK, 0 rows affected, 2 warnings (0.01 sec) mysql> start slave; Query OK, 0 rows affected (0.00 sec) //查看从服务器状态 mysql> show slave status \G *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 192.168.153.152 Master_User: repl Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin.000004 Read_Master_Log_Pos: 154 Relay_Log_File: mysql-relay-bin.000002 Relay_Log_Pos: 320 Relay_Master_Log_File: mysql-bin.000004 Slave_IO_Running: Yes //此处必须为Yes Slave_SQL_Running: Yes //此处必须为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: 527 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: eec564cd-7744-11e9-8dfe-000c29c97322 Master_Info_File: /opt/data/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)
3.2.5 测试验证
在主服务器的liucongrong库的student表中插入数据
mysql> create database liucongrong; Query OK, 1 row affected (0.00 sec) mysql> use liucongrong; Database changed mysql> create table student(name varchar(100),age tinyint); Query OK, 0 rows affected (0.02 sec) mysql> insert student values ('tom',29),('jerry',20); Query OK, 2 rows affected (0.04 sec) Records: 2 Duplicates: 0 Warnings: 0 mysql> select * from student; +-------+------+ | name | age | +-------+------+ | tom | 29 | | jerry | 20 | +-------+------+ 2 rows in set (0.00 sec)
在从数据库中查看数据是否同步:
mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | | sys | +--------------------+ 4 rows in set (0.00 sec) mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | liucongrong | | mysql | | performance_schema | | sys | +--------------------+ 5 rows in set (0.00 sec) mysql> select * from liucongrong.student; +-------+------+ | name | age | +-------+------+ | tom | 29 | | jerry | 20 | +-------+------+ 2 rows in set (0.00 sec)
4.mysql主从配置
4.1确保从数据库与主数据库里的数据一样
为确保从数据库与主数据库里的数据一样,先全备主数据库并还原到从数据库中
//先查看主库有哪些库 mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | liucongrong | | mysql | | performance_schema | | sys | +--------------------+ 5 rows in set (0.00 sec) //再查看从库有哪些库 mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | | sys | +--------------------+ 4 rows in set (0.00 sec) //全备主库 //全备主库时需要另开一个终端,给数据库加上读锁,避免在备份期间有其他人在写入导致数据不一致 mysql> FLUSH TABLES WITH READ LOCK; Query OK, 0 rows affected (0.00 sec) //此锁表的终端必须在备份完成以后才能退出 //备份主库并将备份文件传送到从库 [root@localhost ~]# mysqldump -uroot -ply123 --all-databases > /root/all.sql mysqldump: [Warning] Using a password on the command line interface can be insecure. [root@localhost ~]# ls all.sql anaconda-ks.cfg mysql-5.7.22-linux-glibc2.12-x86_64.tar.gz pass [root@localhost ~]# scp /root/all.sql root@192.168.153.164:/root/ The authenticity of host '192.168.153.164 (192.168.153.164)' can't be established. ECDSA key fingerprint is SHA256:NoDuGXDlaqriTX1RFynwCDbRXu2QrfUpNwZyglaGUdI. ECDSA key fingerprint is MD5:10:35:ff:d9:f7:cd:8a:0a:8d:63:72:11:29:28:d3:fa. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added '192.168.153.164' (ECDSA) to the list of known hosts. root@192.168.153.164's password: Permission denied, please try again. root@192.168.153.164's password: a 100% 784KB 50.3MB/s 00:00 //解除主库的锁表状态,直接退出交互式界面即可 mysql> quit Bye //在从库上恢复主库的备份并查看从库有哪些库,确保与主库一致 [root@localhost ~]# mysql -uroot -ply123 < /root/all.sql mysql: [Warning] Using a password on the command line interface can be insecure. [root@localhost ~]# mysql -uroot -ply123 mysql: [Warning] Using a password on the command line interface can be insecure. Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 4 Server version: 5.7.22 MySQL Community Server (GPL) Copyright (c) 2000, 2018, 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> select * from liucongrong.student; +-------+------+ | name | age | +-------+------+ | tom | 29 | | jerry | 20 | +-------+------+ 2 rows in set (0.00 sec)
4.1.2在主数据库里创建一个同步账号授权给从数据库使用
mysql> CREATE USER 'repl'@'192.168.153.164' IDENTIFIED BY 'repl123'; Query OK, 0 rows affected (0.01 sec) mysql> GRANT REPLICATION SLAVE ON *.* TO 'repl'@'192.168.153.164'; Query OK, 0 rows affected (0.00 sec) mysql> flush privileges; Query OK, 0 rows affected (0.00 sec)
4.1.3配置主数据库
[root@localhost ~]# vim /etc/my.cnf //在[mysqld]这段的后面加上如下内容 [mysqld] datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock log-bin=mysql-bin //启用binlog日志 server-id=1 //数据库服务器唯一标识符,主库的server-id值必须比从库的小 symbolic-links=0 log-error=/var/log/mysqld.log pid-file=/var/run/mysqld/mysqld.pid //重启mysql服务 [root@localhost ~]# /etc/init.d/mysqld restart Shutting down MySQL.. SUCCESS! Starting MySQL. SUCCESS! [root@localhost ~]# ss -antl State Recv-Q Send-Q Local Address:Port Peer Address:Port LISTEN 0 128 *:22 *:* LISTEN 0 100 127.0.0.1:25 *:* LISTEN 0 128 :::22 :::* LISTEN 0 100 ::1:25 :::* LISTEN 0 80 :::3306 :::* //查看主库的状态 [root@localhost ~]# mysql -uroot -ply123 mysql: [Warning] Using a password on the command line interface can be insecure. Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 2 Server version: 5.7.22-log MySQL Community Server (GPL) Copyright (c) 2000, 2018, 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 master status; +------------------+----------+--------------+------------------+-------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set | +------------------+----------+--------------+------------------+-------------------+ | mysql-bin.000001 | 154 | | | | +------------------+----------+--------------+------------------+-------------------+ 1 row in set (0.00 sec)
4.1.3 配置从数据库
[root@localhost ~]# vim /etc/my.cnf //添加如下内容 [mysqld] datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock server-id=4 //设置从库的唯一标识符,从库的server-id值必须小于主库的该值 relay-log=mysql-relay-bin //启用中继日志relay-log symbolic-links=0 log-error=/var/log/mysqld.log pid-file=/var/run/mysqld/mysqld.pid //重启从库的mysql服务 [root@localhost ~]# systemctl restart mysqld [root@localhost ~]# ss -antl State Recv-Q Send-Q Local Address:Port Peer Address:Port LISTEN 0 128 *:22 *:* LISTEN 0 100 127.0.0.1:25 *:* LISTEN 0 128 :::22 :::* LISTEN 0 100 ::1:25 :::* LISTEN 0 80 :::3306 :::* //配置并启动主从复制 mysql> CHANGE MASTER TO -> MASTER_HOST='192.168.153.152', -> MASTER_USER='repl', -> MASTER_PASSWORD='repl123', -> MASTER_LOG_FILE='mysql-bin.000004', -> MASTER_LOG_POS=1443; Query OK, 0 rows affected, 2 warnings (0.01 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: 192.168.153.152 Master_User: repl Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin.000004 Read_Master_Log_Pos: 1443 Relay_Log_File: mysql-relay-bin.000002 Relay_Log_Pos: 320 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: 1443 Relay_Log_Space: 527 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: eec564cd-7744-11e9-8dfe-000c29c97322 Master_Info_File: /opt/data/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)
4.1.4测试验证
在主库插入数据
mysql> insert student values ('zhangsan',20),('lisi',18); Query OK, 2 rows affected (0.01 sec) Records: 2 Duplicates: 0 Warnings: 0 mysql> select * from student; +----------+------+ | name | age | +----------+------+ | tom | 29 | | jerry | 20 | | zhangsan | 20 | | lisi | 18 | +----------+------+ 4 rows in set (0.00 sec)
在从数据库中查看数据是否同步:
Channel_Name: Master_TLS_Version: 1 row in set (0.00 sec) mysql> select * from liucongrong.student; +----------+------+ | name | age | +----------+------+ | tom | 29 | | jerry | 20 | | zhangsan | 20 | | lisi | 18 | +----------+------+ 4 rows in set (0.00 sec)
来源:https://www.cnblogs.com/ly0629/p/10873487.html