mysql二进制日志定时备份

MySQL 完全备份与增量备份

场景要求：对 company 数据库进行自动备份：完全备份：每周六 01:00 执行，保存至 /backup/mysql/full/。增量备份：每天 03:00 执行，保存至 /backup/mysql/increment/。使用 Shell 脚本 + Crontab 实现自动备份，通过 Binlog 实现增量备份，并完成数据恢复测试。

两项定时任务：

每周六 01:00：使用 mysqldump 备份所有数据库到 /backup/mysql/full/。
每天 03:00：切换 Binlog，并将已关闭的 Binlog 文件归档到 /backup/mysql/increment/。

兼容 MySQL 5.7 / 8.0 和 CentOS 7。

一、完整 Shell 脚本

创建文件：

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vi /usr/local/bin/mysql_backup.sh

以下为完整内容：

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#!/bin/bash

user="root"
pass="Root@123456"

export MYSQL_PWD="$pass"

full="/backup/mysql/full"
inc="/backup/mysql/increment"
marker="/backup/mysql/midnight_binlog"

set -o pipefail

mkdir -p "$full" "$inc" || exit 1

if [ "$1" = "rotate" ]; then
    mysql -u"$user" -e "FLUSH BINARY LOGS" || exit 1

    current=$(mysql -u"$user" -Nse \
        "SHOW MASTER STATUS" | awk '{print $1}') || exit 1

    [ -n "$current" ] || exit 1

    echo "$current" > "$marker.tmp" &&
        mv "$marker.tmp" "$marker" || exit 1

elif [ "$1" = "full" ]; then
    [ "$(date +%w)" = "6" ] || exit 0

    backup_date=$(date +%F_%H-%M-%S)
    backup_file="$full/full_$backup_date.sql.gz"

    if ! mysqldump -u"$user" --all-databases \
        --single-transaction --master-data=2 \
        --routines --events --triggers \
        | gzip > "$backup_file"; then
        rm -f "$backup_file"
        exit 1
    fi

elif [ "$1" = "increment" ]; then
    [ -s "$marker" ] || exit 1
    marker_name=$(cat "$marker")

    index=$(mysql -u"$user" -Nse \
        "SHOW VARIABLES LIKE 'log_bin_index'" | awk '{print $2}') || exit 1

    [ -n "$index" ] && [ -r "$index" ] || exit 1

    found=0

    while IFS= read -r log; do
        [ -n "$log" ] || continue
        [[ "$log" != /* ]] && log="$(dirname "$index")/$log"

        name=$(basename "$log")

        if [ "$name" = "$marker_name" ]; then
            found=1
            break
        fi

        [ -f "$inc/$name" ] && continue

        cp "$log" "$inc/$name.tmp" &&
            mv "$inc/$name.tmp" "$inc/$name" || exit 1
    done < "$index"

    [ "$found" = "1" ] || exit 1

else
    echo "Usage: $0 rotate|full|increment"
    exit 1
fi

二、定时任务及赋权

执行 crontab -e，添加以下三条：

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0 0 * * * /usr/local/bin/mysql_backup.sh rotate >> /var/log/mysql_backup.log 2>&1
0 1 * * 6 /usr/local/bin/mysql_backup.sh full >> /var/log/mysql_backup.log 2>&1
0 3 * * * /usr/local/bin/mysql_backup.sh increment >> /var/log/mysql_backup.log 2>&1

赋予脚本执行权限：

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chmod +x /usr/local/bin/mysql_backup.sh

三、每天的执行顺序

时间操作

00:00 刷新 Binlog，并记录新日志文件名作为归档边界

01:00（周六）执行全量热备份

03:00 归档边界之前已关闭的 Binlog，也就是前一天的日志

四、手动测试

先手动测试增量归档：

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/usr/local/bin/mysql_backup.sh increment

周六测试全量备份：

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/usr/local/bin/mysql_backup.sh full

查看备份文件：

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ls -lh /backup/mysql/full/
ls -lh /backup/mysql/increment/
tail -30 /var/log/mysql_backup.log