首先在进行增量备份之前需要查看一下配置文件，查看 log_bin 是否开启，因为要做增量备份首先要开启 log_bin 。首先，进入到 myslq 命令行，输入如下命令：
show variables like '%log_bin%';
如下命令所示，则为未开启
mysql> show variables like '%log_bin%';
+---------------------------------+-------+
| Variable_name | Value |
+---------------------------------+-------+
| log_bin | OFF |
| log_bin_basename | |
| log_bin_index | |
| log_bin_trust_function_creators | OFF |
| log_bin_use_v1_row_events | OFF |
| sql_log_bin | ON |
+---------------------------------+-------+
修改 MySQL 配置项到如下代码段：vim /etc/mysql/mysql.conf.d/mysqld.cnf
# Copyright (c) 2014, 2016, Oracle and/or its affiliates. All rights reserved.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; version 2 of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
#
# The MySQL Server configuration file.
#
# For explanations see
# http://dev.mysql.com/doc/mysql/en/server-system-variables.html
[mysqld]
pid-file = /var/run/mysqld/mysqld.pid
socket = /var/run/mysqld/mysqld.sock
datadir = /var/lib/mysql
#log-error = /var/log/mysql/error.log
# By default we only accept connections from localhost
如果是mariadb，则应该修改/etc/my.cnf.d/server.cnf,将代码添加在[mysqld]下面
#
# These groups are read by MariaDB server.
# Use it for options that only the server (but not clients) should see
#
# See the examples of server my.cnf files in /usr/share/mysql/
#
# this is read by the standalone daemon and embedded servers
[server]
# this is only for the mysqld standalone daemon
[mysqld]
#2021-07-27添加，开启log-bin
# binlog日志路径，格式为mariadb-log.00000*,递增
log-bin=mysql-bin
#binary log 最大的大小
max-binlog-size=1G
# binlog日志保留天数
expire_logs_days=180
# binlog日志有三种格式，分别是Statement、MiXED、ROW
binlog_format=row
#开启log-bin 修改结束
# this is only for embedded server
[embedded]
# This group is only read by MariaDB-5.5 servers.
# If you use the same .cnf file for MariaDB of different versions,
# use this group for options that older servers don't understand
[mysqld-5.5]
# These two groups are only read by MariaDB servers, not by MySQL.
# If you use the same .cnf file for MySQL and MariaDB,
# you can put MariaDB-only options here
[mariadb]
[mariadb-5.5]
修改之后，重启 mysql 服务，mysql和mariadb命令不同
systemctl restart myslqd # mysql
systemctl restart mariadb.service #mariadb
输入：
show variables like '%log_bin%';
状态如下：
mysql> show variables like '%log_bin%';
+---------------------------------+--------------------------------+
| Variable_name | Value |
+---------------------------------+--------------------------------+
| log_bin | ON |
| log_bin_basename | /var/lib/mysql/mysql-bin |
| log_bin_index | /var/lib/mysql/mysql-bin.index |
| log_bin_trust_function_creators | OFF |
| log_bin_use_v1_row_events | OFF |
| sql_log_bin | ON |
+---------------------------------+--------------------------------+
好了，做好了充足的准备，那我们就开始学习增量备份了。
查看当前使用的 mysql_bin.000*** 日志文件，
show master status;
状态如下：
mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000015 | 610 | | | |
+------------------+----------+--------------+------------------+-------------------+
当前正在记录日志的文件名为 mysql-bin.000015 。（日志文件根据刚才配置，在/var/lib/mysql目录下）
当前数据库中有如下数据：
mysql> select * from users;
+-------+------+----+
| name | sex | id |
+-------+------+----+
| zone | 0 | 1 |
| zone1 | 1 | 2 |
| zone2 | 0 | 3 |
+-------+------+----+
我们插入一条数据：
insert into `zone`.`users` ( `name`, `sex`, `id`) values ( 'zone3', '0', '4');
查看效果：
mysql> select * from users;
+-------+------+----+
| name | sex | id |
+-------+------+----+
| zone | 0 | 1 |
| zone1 | 1 | 2 |
| zone2 | 0 | 3 |
| zone3 | 0 | 4 |
+-------+------+----+
我们执行如下命令，使用新的日志文件：
mysqladmin -uroot -123456 flush-logs
日志文件从 mysql-bin.000015 变为 mysql-bin.000016，而 mysql-bin.000015 则记录着刚刚 insert 命令的日志。上句代码的效果如下：
mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000016 | 154 | | | |
+------------------+----------+--------------+------------------+-------------------+
那么到现在为止，其实已经完成了增量备份了。
恢复增量备份
那么现在将刚刚插入的数据删除，效果如下：
delete from `zone`.`users` where `id`='4'
mysql> select * from users;
+-------+------+----+
| name | sex | id |
+-------+------+----+
| zone | 0 | 1 |
| zone1 | 1 | 2 |
| zone2 | 0 | 3 |
+-------+------+----+
那么现在就是重点时间了，从 mysql-bin.000015 中恢复数据：
mysqlbinlog /var/lib/mysql/mysql-bin.000015 | mysql -uroot -p123456 zone;
上一句代码指定了，需要恢复的 mysql_bin 文件，指定了用户名：root 、密码：123456 、数据库名：zone。效果如下：
mysql> select * from users;
+-------+------+----+
| name | sex | id |
+-------+------+----+
| zone | 0 | 1 |
| zone1 | 1 | 2 |
| zone2 | 0 | 3 |
| zone3 | 0 | 4 |
+-------+------+----+
OK，整一个增量备份的操作流程都在这里了，那么我们如何将它写成脚本文件呢，代码如下：
#!/bin/bash
#在使用之前，请提前创建以下各个目录
backupDir=/usr/local/work/backup/daily
#增量备份时复制mysql-bin.00000*的目标目录，提前手动创建这个目录
mysqlDir=/var/lib/mysql
#mysql的数据目录
logFile=/usr/local/work/backup/bak.log
BinFile=/var/lib/mysql/mysql-bin.index
#mysql的index文件路径，放在数据目录下的
mysqladmin -uroot -p123456 flush-logs
#这个是用于产生新的mysql-bin.00000*文件
# wc -l 统计行数
# awk 简单来说awk就是把文件逐行的读入，以空格为默认分隔符将每行切片，切开的部分再进行各种分析处理。
Counter=`wc -l $BinFile |awk '{print $1}'`
NextNum=0
#这个for循环用于比对$Counter,$NextNum这两个值来确定文件是不是存在或最新的
for file in `cat $BinFile`
do
base=`basename $file`
echo $base
#basename用于截取mysql-bin.00000*文件名，去掉./mysql-bin.000005前面的./
NextNum=`expr $NextNum + 1`
if [ $NextNum -eq $Counter ]
then
echo $base skip! >> $logFile
else
dest=$backupDir/$base
if(test -e $dest)
#test -e用于检测目标文件是否存在，存在就写exist!到$logFile去
then
echo $base exist! >> $logFile
else
cp $mysqlDir/$base $backupDir
echo $base copying >> $logFile
fi
fi
done
echo `date +"%Y年%m月%d日 %H:%M:%S"` $Next Bakup succ! >> $logFile
#NODE_ENV=$backUpFolder@$backUpFileName /root/node/v8.11.3/bin/node /usr/local/upload.js
定时备份
输入如下命令，进入定时任务编辑界面：
crontab -e
添加如下命令，其意思为：每分钟执行一次备份脚本
* * * * * sh /usr/your/path/mysqlbackup.sh