MySQL（备份恢复、主从复制读写分离）

1.mysql的备份与恢复

数据备份的重要性

在生产环境中，数据的安全性至关重要
任何数据的丢失都可能产生严重的后果
造成数据丢失的原因
- 程序错误
- 人为操作错误
- 运算错误
- 磁盘故障
- 灾难（如火灾、地震）和盗窃

数据库备份的分类

从物理与逻辑的角度，备份可分为

物理备份：对数据库操作系统的物理文件（如数据文件、日志文件等）的备份
- 物理备份方法
  - 冷备份（脱机备份）：是在关闭数据库的时候进行的
  - 热备份（联机备份）：数据库处于运行状态，依赖于数据库的日志文件
  - 温备份：数据库锁定表格（不可写入但可读）的状态下进行备份操作
逻辑备份：对数据库逻辑组件（如：表等数据库对象）的备份

常见的备份方法

物理冷备
- 备份时数据库处于关闭状态，直接打包数据库文件
- 备份速度快，恢复时也是最简单的
专用备份工具mydump或mysqlhotcopy
- mysqldump常用的逻辑备份工具
- mysqlhotcopy仅拥有备份MylSAM和ARCHIVE表
启用二进制日志进行增量备份
- 进行增量备份，需要刷新二进制日志
第三方工具备份
- 免费的MvSQL热备份软件PerconaXtraBackup

冷备份

备份（推荐写法）
$root@mysql01 \~\]# systemctl stop mysqld # 先停止服务 \[root@mysql01 \~\]# cd /usr/local/mysql/data \[root@mysql01 data\]# mkdir /mysql_bak \[root@mysql01 data\]# tar czf /mysql_bak/mysql-backup-$(date +%F).tar.gz \* \[root@mysql01 data\]# systemctl start mysqld # 备份完成后启动服务 #测试服务正常 # 删除数据 \[root@mysql01 \~\]# systemctl stop mysqld # 先停止服务 \[root@mysql01 \~\]# rm -rf /usr/local/mysql/data/\* # 清空数据目录（谨慎操作！） #再次开启测试，发现数据库坏了 \[root@mysql01 \~\]# systemctl start mysqld #停止数据库，恢复数据库 \[root@mysql01 \~\]# systemctl stop mysqld \[root@mysql01 \~\]# tar xzf /mysql_bak/mysql-backup-2025-10-15.tar.gz -C /usr/local/mysql/data/ \[root@mysql01 \~\]# chown -R mysql:mysql /usr/local/mysql/data # 恢复权限 \[root@mysql01 \~\]# systemctl start mysqld # 启动服务 #再次测试，发现数据库恢复了$

逻辑备份

#备份数据库
$root@mysql01 \~\]# systemctl start mysqld \[root@mysql01 \~\]# mysqldump -u root -pschool \> /mysql_bak/school.sql Enter password: \[root@mysql01 \~\]# ls /mysql_bak/school.sql mysql_bak/school.sql \[root@mysql01 \~\]# cat /mysql_bak/school.sql #备份多个数据库 \[root@mysql01 \~\]# mysqldump -u root -p --databases school mysql \> /mysql_bak/school-mysql.sql Enter password: \[root@mysql01 \~\]# cat /mysql_bak/school-mysql.sql #备份所有数据库 \[root@mysql01 \~\]# mysqldump -u root -p --opt --all-databases \> /mysql_bak/all.sql Enter password: \[root@mysql01 \~\]# cat /mysql_bak/all.sql #备份整个表 \[root@mysql01 \~\]# mysqldump -u root -p school info \> /mysql_bak/info.sql Enter password: \[root@mysql01 \~\]# cat /mysql_bak/info.sql$

恢复数据

$root@mysql01 \~\]# mysql -u root -p Enter password: mysql\> use school mysql\> show tables; +------------------+ \| Tables_in_school \| +------------------+ \| info \| +------------------+ 1 row in set (0.00 sec) #永久删除info表 mysql\> drop table info; Query OK, 0 rows affected (0.01 sec) #从备份文件恢复表（核心操作） mysql\> source /mysql_bak/info.sql mysql\> show tables; +------------------+ \| Tables_in_school \| +------------------+ \| info \| +------------------+ 1 row in set (0.00 sec)$

增量备份

$root@mysql01 \~\]# vim /etc/my.cnf ------------------------ \[mysqld$
log-bin=mysql-bin #这段下面最后加一行

$root@web-server \~\]# systemctl restart mysqld.service \[root@mysql01 \~\]# ls /usr/local/mysql/data/ auto.cnf client-cert.pem ibdata1 ibtmp1 mysql-bin.index public_key.pem server-key.pem ca-key.pem client-key.pem ib_logfile0 mysql performance_schema school sys ca.pem ib_buffer_pool ib_logfile1 mysql-bin.000001 private_key.pem server-cert.pem #先进行完整性备份 \[root@mysql01 \~\]# mysqldump -uroot -p school \> /opt/school.sql Enter password: #日志刷新生效 \[root@mysql01 \~\]# mysqladmin -uroot -p flush-logs Enter password: #新产生的mysql-bin.000002只记录上次刷新后的操作 \[root@mysql01 \~\]# ls /usr/local/mysql/data/ auto.cnf client-cert.pem ibdata1 ibtmp1 mysql-bin.000002 private_key.pem server-cert.pem ca-key.pem client-key.pem ib_logfile0 mysql mysql-bin.index public_key.pem server-key.pem ca.pem ib_buffer_pool ib_logfile1 mysql-bin.000001 performance_schema school sys \[root@mysql01 \~\]# mysql -uroot -p Enter password: ---------------------------------------- mysql\> use school; mysql\> select \* from info; +----+--------+-------+---------+-------+ \| id \| name \| score \| address \| hobby \| +----+--------+-------+---------+-------+ \| 1 \| 张三 \| 90.00 \| 广州 \| 1 \| \| 2 \| 叶凡 \| 91.00 \| 伦敦 \| 2 \| \| 4 \| 曹操 \| 66.50 \| 合肥 \| 4 \| +----+--------+-------+---------+-------+ 3 rows in set (0.00 sec) #再次插入数据生产增量备份 mysql\> insert into info (name,score,address,hobby) values ('美猴王',75,'武汉',1); Query OK, 1 row affected (0.00 sec) mysql\> exit Bye \[root@mysql01 \~\]# mysqladmin -uroot -p flush-log Enter password: #新产生mysql-bin.000003日志记录insert操作 \[root@mysql01 \~\]# ls /usr/local/mysql/data/ auto.cnf client-cert.pem ibdata1 ibtmp1 mysql-bin.000002 performance_schema school sys ca-key.pem client-key.pem ib_logfile0 mysql mysql-bin.000003 private_key.pem server-cert.pem ca.pem ib_buffer_pool ib_logfile1 mysql-bin.000001 mysql-bin.index public_key.pem server-key.pem \[root@mysql01 \~\]# mysql -uroot -p Enter password: --------------------------------------------------------------- mysql\> use school; 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\> insert into info (name,score,address,hobby) values ('超人',83,'上海',2); Query OK, 1 row affected (0.00 sec) mysql\> select \* from info; +----+-----------+-------+---------+-------+ \| id \| name \| score \| address \| hobby \| +----+-----------+-------+---------+-------+ \| 1 \| 张三 \| 90.00 \| 广州 \| 1 \| \| 2 \| 叶凡 \| 91.00 \| 伦敦 \| 2 \| \| 4 \| 曹操 \| 66.50 \| 合肥 \| 4 \| \| 5 \| 美猴王 \| 75.00 \| 武汉 \| 1 \| \| 6 \| 超人强 \| 83.00 \| 上海 \| 2 \| +----+-----------+-------+---------+-------+ 5 rows in set (0.00 sec) mysql\> exit Bye #刷新日志生效 \[root@mysql01 \~\]# mysqladmin -uroot -p flush-log Enter password: #环境准备 \[root@mysql01 \~\]# mysql -uroot -p Enter password: -------------------------------------------------------------- mysql\> use school; 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 #删除内容 mysql\> delete from info where id=6; Query OK, 1 row affected (0.00 sec) mysql\> delete from info where id=5; Query OK, 1 row affected (0.01 sec) mysql\> select \* from info; +----+--------+-------+---------+-------+ \| id \| name \| score \| address \| hobby \| +----+--------+-------+---------+-------+ \| 1 \| 张三 \| 90.00 \| 广州 \| 1 \| \| 2 \| 叶凡 \| 91.00 \| 伦敦 \| 2 \| \| 4 \| 曹操 \| 66.50 \| 合肥 \| 4 \| +----+--------+-------+---------+-------+ 3 rows in set (0.00 sec) mysql\> exit Bye \[root@mysql01 \~\]# ls /usr/local/mysql/data/ auto.cnf client-cert.pem ibdata1 ibtmp1 mysql-bin.000002 mysql-bin.index public_key.pem server-key.pem ca-key.pem client-key.pem ib_logfile0 mysql mysql-bin.000003 performance_schema school sys ca.pem ib_buffer_pool ib_logfile1 mysql-bin.000001 mysql-bin.000004 private_key.pem server-cert.pem #查看日志文件，vim看日志是乱码 \[root@mysql01 \~\]# mysqlbinlog --no-defaults --base64-output=decode-rows -v /usr/local/mysql/data/mysql-bin.000003 \[root@mysql01 \~\]# mysqlbinlog --no-defaults --base64-output=decode-rows -v /usr/local/mysql/data/mysql-bin.000004 #恢复操作，恢复时如果被拒绝，是有其他mysql进程占用了 \[root@mysql01 \~\]# mysqlbinlog --no-defaults /usr/local/mysql/data/mysql-bin.000003 \| mysql -uroot -p Enter password: #验证 \[root@web-server \~\]# mysql -uroot -p Enter password: --------------------------------------------------------------- mysql\> select \* from info; +----+--------+-------+---------+-------+ \| id \| name \| score \| address \| hobby \| +----+--------+-------+---------+-------+ \| 1 \| 张三 \| 90.00 \| 广州 \| 1 \| \| 2 \| 叶凡 \| 91.00 \| 伦敦 \| 2 \| \| 4 \| 曹操 \| 66.50 \| 合肥 \| 4 \| \| 6 \| 超人强 \| 83.00 \| 上海 \| 2 \| +----+--------+-------+---------+-------+ 4 rows in set (0.00 sec)$

2.主从复制和读写分离

使用目标：数据冗余和灾难恢复；提升并发能力、避免锁冲突。

MySQL读写分离原理

只在主服务器上写，只在从服务器上读
主数据库处理事务性查询，从数据库处理SELECT查询
数据库复制用于将事务性查询的变更同步到集群中的从数据库
读写分离方案
- 基于程序代码内部实现
- 基于中间代理层实现
  - MySQL-Proxy
  - Amoeba

在每个事务更新数据完成之前，Master将这些改变记录进二进制日志。写入二进制日志完成后，Master通知存储引擎提交事务。
Slave将Master 的 Binary log复制到其中继日志(Relay log)。首先，Slave开始一个工作线程-I/0线程,I/0线程在Master上打开一个普通的连接，然后开始Binlog dump process。Binlog dump process从Master 的二进制日志中读取事件，如果已经跟上Master，它会睡眠并等待Master产生新的事件。I/0线程将这些事件写入中继日志。
SQLslavethread(SQL从线程）处理该过程的最后一步。SQL线程从中继日志读取事件，并重放其中的事件而更新Slave数据，使其与Master中的数据保持一致。只要该线程与I/0线程保持一致，中继日志通常会位于0S的缓存中，所以中继日志的开销很小。复制过程有一个很重要的限制，即复制在Slave上是串行化的，也就是说Master上的并行更新操作不能在Slave上并行操作。

实验拓扑图

使用Centos-7-template模板克隆产生应用客户端和amoeba

使用mysql模板克隆产生mysql主服务器，mysql从节点1，mysql从节点2

根据下表，将IP地址，主机名更改好

主机名	IP地址	作用
mysql-master	192.168.108.101	mysql主服务器
mysql-slave01	192.168.108.102	mysql从节点1
mysql-slave02	192.168.108.103	mysql从节点2
amoeba	192.168.108.110	amoeba
mysql-client	192.168.108.111	应用客户端

时间同步

所有节点
$root@mysql-all \~\]# ntpdate ntp.aliyun.com \[root@mysql-all \~\]# date -R \[root@mysql-all \~\]# setenforce 0$

mysql主从服务器配置

mysql主服务器配置

$root@mysql-master \~\]# vim /etc/my.cnf server-id = 11 log-bin = master-bin #主服务器日志文件 log-slave-updates = true #从服务器更新二进制日志 \[root@mysql-master \~\]# systemctl restart mysqld \[root@mysql-master \~\]# mysql -u root -p Enter password: mysql\> GRANT REPLICATION SLAVE ON \*.\* TO 'myslave'@'192.168.108.%' IDENTIFIED BY '123456'; Query OK, 0 rows affected, 1 warning (0.01 sec) mysql\> FLUSH PRIVILEGES; Query OK, 0 rows affected (0.00 sec) mysql\> show master status; +-------------------+----------+--------------+------------------+-------------------+ \| File \| Position \| Binlog_Do_DB \| Binlog_Ignore_DB \| Executed_Gtid_Set \| +-------------------+----------+--------------+------------------+-------------------+ \| master-bin.000001 \| 604 \| \| \| \| +-------------------+----------+--------------+------------------+-------------------+ 1 row in set (0.00 sec) #记录一下 master-bin.000001 \| 604 #检查有没有master-bin.000001 \[root@mysql-master \~\]# ls /usr/local/mysql/data auto.cnf ibdata1 ib_logfile1 master-bin.000001 mysql sys ib_buffer_pool ib_logfile0 ibtmp1 master-bin.index performance_schema$

mysql从服务器配置

mysql-slave01,mysql-slave02都要做如下操作

#主从是克隆的要做这个操作，否则UUID一致
$root@mysql-slave01 \~\]# systemctl stop mysqld \[root@mysql-slave01 \~\]# rm -f /usr/local/mysql/data/auto.cnf \[root@mysql-slave01 \~\]# systemctl start mysqld \[root@mysql-slave01 \~\]# vim /etc/my.cnf server-id = 22 #另外一台为23 relay-log = relay-log-bin #从主服务器上同步日志文件记录到本地 relay-log-index = slave-relay-bin.index #定义relay-log的位置和名称 \[root@mysql-slave01 \~\]# systemctl restart mysqld \[root@mysql-slave01 \~\]# mysql -u root -p Enter password: mysql\> change master to master_host='192.168.108.101',master_user='myslave',master_password='123456',master_log_file='master-bin.000001',master_log_pos=604; #master_log_file，master_log_pos与前面查询的相同 Query OK, 0 rows affected, 2 warnings (0.03 sec) mysql\> start slave; Query OK, 0 rows affected (0.02 sec) mysql\> show slave status\\G; \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* 1. row \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* Slave_IO_State: Waiting for master to send event Master_Host: 192.168.108.101 Master_User: myslave Master_Port: 3306 Connect_Retry: 60 Master_Log_File: master-bin.000001 Read_Master_Log_Pos: 604 Relay_Log_File: relay-log-bin.000002 Relay_Log_Pos: 321 Relay_Master_Log_File: master-bin.000001 Slave_IO_Running: Yes #Yes Slave_SQL_Running: Yes #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: 604 Relay_Log_Space: 526 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: 11 Master_UUID: 5d895caf-a1e0-11f0-b3ec-000c29866c0f Master_Info_File: /usr/local/mysql/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) ERROR: No query specified #mysql-slave02 \[root@mysql-slave02 \~\]# systemctl stop mysqld \[root@mysql-slave02 \~\]# rm -f /usr/local/mysql/data/auto.cnf \[root@mysql-slave02 \~\]# systemctl start mysqld \[root@mysql-slave02 \~\]# vim /etc/my.cnf server-id = 23 relay-log = relay-log-bin relay-log-index = slave-relay-bin.index \[root@mysql-slave02 \~\]# systemctl restart mysqld \[root@mysql-slave02 \~\]# mysql -u root -p Enter password: mysql\> change master to master_host='192.168.108.101',master_user='myslave',master_password='123456',master_log_file='master-bin.000001',master_log_pos=604; Query OK, 0 rows affected, 2 warnings (0.04 sec) mysql\> start slave; Query OK, 0 rows affected (0.01 sec) mysql\> show slave status\\G; \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* 1. row \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* Slave_IO_State: Waiting for master to send event Master_Host: 192.168.108.101 Master_User: myslave Master_Port: 3306 Connect_Retry: 60 Master_Log_File: master-bin.000001 Read_Master_Log_Pos: 604 Relay_Log_File: relay-log-bin.000002 Relay_Log_Pos: 321 Relay_Master_Log_File: master-bin.000001 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: 604 Relay_Log_Space: 526 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: 11 Master_UUID: 5d895caf-a1e0-11f0-b3ec-000c29866c0f Master_Info_File: /usr/local/mysql/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) ERROR: No query specified$

验证主从同步

主服务器上:
$root@mysql-master \~\]# mysql -uroot -phuawei mysql\> create database school; Query OK, 1 row affected (0.01 sec) mysql\> use school; CREATE TABLE student ( id int UNSIGNED AUTO_INCREMENT PRIMARY KEY, name VARCHAR(20) NOT NULL, age tinyint UNSIGNED, #height DECIMAL(5,2), gender ENUM('M','F') default 'M' )ENGINE=InnoDB AUTO_INCREMENT=10 DEFAULT CHARSET=utf8mb4; mysql\> insert student (name,age)values('路飞',20); # 去从服务器上 show databases; \[root@mysql-slave01 \~\]# mysql -uroot -phuawei mysql\> select \* from school.student; +----+--------+------+--------+ \| id \| name \| age \| gender \| +----+--------+------+--------+ \| 10 \| 路飞 \| 20 \| M \| +----+--------+------+--------+ 1 row in set (0.00 sec)$

amoeba服务器

#普通linux克隆
$root@amoeba \~\]# hostnamectl set-hostname amoeba \[root@amoeba \~\]# systemctl stop firewalld.service \[root@amoeba \~\]# setenforce 0 \[root@amoeba \~\]# chmod +x jdk-6u14-linux-x64.bin \[root@amoeba \~\]# ./jdk-6u14-linux-x64.bin 到yes的时候,输入yes按enter \[root@amoeba \~\]# mv jdk1.6.0_14/ /usr/local/jdk1.6 \[root@amoeba \~\]# vim /etc/profile 最下面加 export JAVA_HOME=/usr/local/jdk1.6 #java家目录 export CLASSPATH=$CLASSPATH:$JAVA_HOME/lib:$JAVA_HOME/jre/lib #类环境和jre export PATH=$JAVA_HOME/lib:$JAVA_HOME/jre/bin/:$PATH:$HOME/bin export AMOEBA_HOME=/usr/local/amoeba #指定amoeba路径 export PATH=$PATH:$AMOEBA_HOME/bin \[root@amoeba \~\]# source /etc/profile \[root@amoeba \~\]# mkdir /usr/local/amoeba \[root@amoeba \~\]# tar zxvf amoeba-mysql-binary-2.2.0.tar.gz -C /usr/local/amoeba/ \[root@amoeba \~\]# chmod -R 755 /usr/local/amoeba/ #执行结果显示amoeba start\|stop说明安装成功 \[root@amoeba \~\]# /usr/local/amoeba/bin/amoeba amoeba start\|stop$

在三台mysql上添加权限开放给amoeba访问

#amooba访问数据库的账号

#mysql-master

mysql> grant all on *.* to test@'192.168.108.%' identified by '123.com';

#mysql-slave01

mysql> grant all on *.* to test@'192.168.108.%' identified by '123.com';

#mysql-slave02

mysql> grant all on *.* to test@'192.168.108.%' identified by '123.com';

回到amoeba服务器

$root@amoeba \~\]# cd /usr/local/amoeba/ \[root@amoeba amoeba\]# vim conf/amoeba.xml ---30行-- \amoeba\123456\ #客户端访问ameoba密码 ---117和120-去掉注释- 115行 \master\ 116 117 118行\master\ 119行\slaves\ 120 \[root@amoeba amoeba\]# vim conf/dbServers.xml #数据库配置 ---23--注意！！！（mysql5.7，默认没有test数据库所以需要修改为mysql数据库）-（mysql5.5直接忽略）-- \$

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