个人博客:mysql数据恢复，binlog详解
binlog日志恢复数据,是挽救错误操作和数据损坏一根救命稻草，所以认识和使用binglog对于技术人员还是很有必要的
binlog一般用于
- 主从复制 中 master节点开启binlog把二进制日志传递给slave节点达到主从数据一致
- 第二点自然是用于数据恢复了，使用mysqlbinlog工具来恢复数据
因为我自己的网站遇到过mysql表被我误删操作,drop table后当时我还是挺淡定的，虽然我不清楚我能不能把数据拯救回来，对于个人网站而言可能都没有主从，也没有把mysql的各项配置设置完美，这种情形下最担心的当然是binlog是否开启了，如果没有开启binlog并且也没有做数据备份，我感觉基本上就GG了
因为我mysql是通过docker容器安装的，所以具体 my.cnf 配置文件的放在哪也忘记了
- 使用 find / -name my.cnf 找到文件在哪
root@0d5861775029:/# find / -name my.cnf
find: '/proc/1/map_files': Operation not permitted
find: '/proc/182/map_files': Operation not permitted
find: '/proc/187/map_files': Operation not permitted
find: '/proc/1601/map_files': Operation not permitted
find: '/proc/1731/map_files': Operation not permitted
find: '/proc/1741/map_files': Operation not permitted
/etc/alternatives/my.cnf
/etc/mysql/my.cnf
/var/lib/dpkg/alternatives/my.cnf
root@0d5861775029:/#
- 查看my.cnf配置找到binlog以及mysql数据存储的位置
#
# 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
secure-file-priv= NULL
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
# Custom config should go here
!includedir /etc/mysql/conf.d/
- 可以看到mysql数据存储的目录是 datadir = /var/lib/mysql 目录中
root@0d5861775029:/etc/mysql# cd /var/lib/mysql/
root@0d5861775029:/var/lib/mysql# ls
#innodb_temp binlog.index client-key.pem ib_logfile1 mysql.ibd server-cert.pem undo_002
auto.cnf ca-key.pem db_blog ibdata1 performance_schema server-key.pem
binlog.000001 ca.pem ib_buffer_pool ibtmp1 private_key.pem sys
binlog.000002 client-cert.pem ib_logfile0 mysql public_key.pem undo_001
上面的前戏都看完了，这其实并非binlog具体使用，而是我个人发现数据目录方式 接下来我将详细介绍binlog的使用
一、开启binlog日志
- 查看binlog是否开启
- ON 表示已经开启
- 查看更多内容可以这样
show variables like 'log_%';
mysql> show variables like 'log_bin';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| log_bin | ON |
+---------------+-------+
1 row in set (0.00 sec)
mysql> show variables like 'log_%';
+----------------------------------------+----------------------------------------+
| Variable_name | Value |
+----------------------------------------+----------------------------------------+
| log_bin | ON |
| log_bin_basename | /var/lib/mysql/binlog |
| log_bin_index | /var/lib/mysql/binlog.index |
| log_bin_trust_function_creators | OFF |
| log_bin_use_v1_row_events | OFF |
| log_error | stderr |
| log_error_services | log_filter_internal; log_sink_internal |
| log_error_suppression_list | |
| log_error_verbosity | 2 |
| log_output | FILE |
| log_queries_not_using_indexes | OFF |
| log_slave_updates | ON |
| log_slow_admin_statements | OFF |
| log_slow_extra | OFF |
| log_slow_slave_statements | OFF |
| log_statements_unsafe_for_binlog | ON |
| log_throttle_queries_not_using_indexes | 0 |
| log_timestamps | UTC |
+----------------------------------------+----------------------------------------+
18 rows in set (0.00 sec)
- 编辑my.cnf开启binlog
在[mysqld] 区块
设置/添加 log-bin=mysql-bin 确认是打开状态(值 mysql-bin 是日志的基本名或前缀名)；
然后重启mysql
二、查看binlog日志操作命令
- 查看所有binlog日志列表
mysql> show logs;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'logs' at line 1
mysql> show master logs;
+---------------+-----------+-----------+
| Log_name | File_size | Encrypted |
+---------------+-----------+-----------+
| binlog.000001 | 3091158 | No |
| binlog.000002 | 141156437 | No |
+---------------+-----------+-----------+
2 rows in set (0.17 sec)
- 查看master状态，也就是最新一个binlog日志编号名称和最后一个操作事件pos结束位置
mysql> show master status;
+---------------+-----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+---------------+-----------+--------------+------------------+-------------------+
| binlog.000002 | 141156437 | | | |
+---------------+-----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
- 刷新log日志，将会产生一个新编号的binlog日志文件
mysql> flush logs;
- 重置(清空)所有binlog日志
mysql> reset master;
三、查看binlog日志内容
- 使用mysqlbinlog命令查看
因为binlog是二进制文件，普通文件查看器都无法打开，必须使用自带的mysqlbinlog命令查看
- mysqlbinlog binlog.000002 使用mysqlbinlog不好观察
- 在mysql中查看binlog日志
mysql> show binlog events [IN 'log_name'] [FROM pos] [LIMIT [offset,] row_count];
选项解析：
IN 'log_name' 指定要查询的binlog文件名(不指定就是第一个binlog文件)
FROM pos 指定从哪个pos起始点开始查起(不指定就是从整个文件首个pos点开始算)
LIMIT [offset,] 偏移量(不指定就是0)
row_count 查询总条数(不指定就是所有行)
截取部分查询结果：
*************************** 20. row ***************************
Log_name: mysql-bin.000021 ----------------------------------------------> 查询的binlog日志文件名
Pos: 11197 ----------------------------------------------------------> pos起始点:
Event_type: Query ----------------------------------------------------------> 事件类型：Query
Server_id: 1 --------------------------------------------------------------> 标识是由哪台服务器执行的
End_log_pos: 11308 ----------------------------------------------------------> pos结束点:11308(即：下行的pos起始点)
Info: use `zyyshop`; INSERT INTO `team2` VALUES (0,345,'asdf8er5') ---> 执行的sql语句
*************************** 21. row ***************************
Log_name: mysql-bin.000021
Pos: 11308 ----------------------------------------------------------> pos起始点:11308(即：上行的pos结束点)
Event_type: Query
Server_id: 1
End_log_pos: 11417
Info: use `zyyshop`; /*!40000 ALTER TABLE `team2` ENABLE KEYS */
*************************** 22. row ***************************
Log_name: mysql-bin.000021
Pos: 11417
Event_type: Query
Server_id: 1
End_log_pos: 11510
Info: use `zyyshop`; DROP TABLE IF EXISTS `type`
- 指定查询 binlog.000002 日志
mysql> show binlog events in 'binlog.000002' limit 10;
+---------------+------+----------------+-----------+-------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Log_name | Pos | Event_type | Server_id | End_log_pos | Info |
+---------------+------+----------------+-----------+-------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| binlog.000002 | 4 | Format_desc | 1 | 124 | Server ver: 8.0.16, Binlog ver: 4 |
| binlog.000002 | 124 | Previous_gtids | 1 | 155 | |
| binlog.000002 | 155 | Anonymous_Gtid | 1 | 234 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| binlog.000002 | 234 | Query | 1 | 482 | CREATE USER 'schwarzeni'@'localhost' IDENTIFIED WITH 'caching_sha2_password' AS '$A$005$H{;gmzB@[}K1i
Bcce80ezg8j3o0qDdYocc1OxBkShlQyzmOV/c4rGP69' /* xid=7 */ |
| binlog.000002 | 482 | Anonymous_Gtid | 1 | 561 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| binlog.000002 | 561 | Query | 1 | 801 | CREATE USER 'cuishifeng'@'%' IDENTIFIED WITH 'caching_sha2_password' AS '$A$005$f8ZshY(9]HPTcaN83yCTNmHs/LQsa2DerCX.ZVgd4InrYiCpj75mA' /* xid=8 */ |
| binlog.000002 | 801 | Anonymous_Gtid | 1 | 878 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| binlog.000002 | 878 | Query | 1 | 968 | FLUSH PRIVILEGES |
| binlog.000002 | 968 | Anonymous_Gtid | 1 | 1047 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| binlog.000002 | 1047 | Query | 1 | 1256 | ALTER USER 'cuishifeng'@'%' IDENTIFIED WITH 'mysql_native_password' AS '*10320381F36BE49A18F09B06A4BC005223975101' /* xid=12 */ |
+---------------+------+----------------+-----------+-------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------+
10 rows in set (0.00 sec)
- 指定查询 binlog.000002 这个文件，从pos点:968开始查起
mysql> show binlog events in 'binlog.000002' from 968 limit 10;
+---------------+------+----------------+-----------+-------------+---------------------------------------------------------------------------------------------------------------------------------+
| Log_name | Pos | Event_type | Server_id | End_log_pos | Info |
+---------------+------+----------------+-----------+-------------+---------------------------------------------------------------------------------------------------------------------------------+
| binlog.000002 | 968 | Anonymous_Gtid | 1 | 1047 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| binlog.000002 | 1047 | Query | 1 | 1256 | ALTER USER 'cuishifeng'@'%' IDENTIFIED WITH 'mysql_native_password' AS '*10320381F36BE49A18F09B06A4BC005223975101' /* xid=12 */ |
| binlog.000002 | 1256 | Anonymous_Gtid | 1 | 1333 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| binlog.000002 | 1333 | Query | 1 | 1423 | flush privileges |
| binlog.000002 | 1423 | Anonymous_Gtid | 1 | 1500 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| binlog.000002 | 1500 | Query | 1 | 1646 | GRANT ALL PRIVILEGES ON *.* TO 'cuishifeng'@'%' /* xid=70 */ |
| binlog.000002 | 1646 | Anonymous_Gtid | 1 | 1723 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| binlog.000002 | 1723 | Query | 1 | 1813 | flush privileges |
| binlog.000002 | 1813 | Anonymous_Gtid | 1 | 1890 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| binlog.000002 | 1890 | Query | 1 | 1968 | FLUSH TABLES |
+---------------+------+----------------+-----------+-------------+---------------------------------------------------------------------------------------------------------------------------------+
10 rows in set (0.00 sec)
从日志中可以看出执行的mysql命令 并且有起始位置，对于恢复数据非常有用
- 查询第一个(最早)的binlog日志
mysql> show binlog events;
四、现在从binlog日志恢复数据
- 常用命令
恢复语法格式：
# mysqlbinlog mysql-bin.0000xx | mysql -u用户名 -p密码 数据库名
常用选项：
--start-position=953 起始pos点
--stop-position=1437 结束pos点
--start-datetime="2013-11-29 13:18:54" 起始时间点
--stop-datetime="2013-11-29 13:21:53" 结束时间点
--database=zyyshop 指定只恢复zyyshop数据库(一台主机上往往有多个数据库，只限本地log日志)
不常用选项：
-u --user=name Connect to the remote server as username.连接到远程主机的用户名
-p --password[=name] Password to connect to remote server.连接到远程主机的密码
-h --host=name Get the binlog from server.从远程主机上获取binlog日志
--read-from-remote-server Read binary logs from a MySQL server.从某个MySQL服务器上读取binlog日志
小结：实际是将读出的binlog日志内容，通过管道符传递给mysql命令。这些命令、文件尽量写成绝对路径；
日志恢复 相当于执行当时DDL语句，如果日志恢复的语句例如你库中存在某个表 日志又执行创建这个表 肯定是走不通的 所以最好指定具体位置恢复
- 查看binlog日志 确定从哪恢复
mysql> show binlog events in 'mysql-bin.000023';
以下为末尾片段：
+------------------+------+------------+-----------+-------------+------------------------------------------------------------+
| Log_name | Pos | Event_type | Server_id | End_log_pos | Info |
+------------------+------+------------+-----------+-------------+------------------------------------------------------------+
| mysql-bin.000023 | 922 | Xid | 1 | 953 | COMMIT /* xid=3820 */ |
| mysql-bin.000023 | 953 | Query | 1 | 1038 | BEGIN |
| mysql-bin.000023 | 1038 | Query | 1 | 1164 | use `zyyshop`; update zyyshop.tt set name='李四' where id=4|
| mysql-bin.000023 | 1164 | Xid | 1 | 1195 | COMMIT /* xid=3822 */ |
| mysql-bin.000023 | 1195 | Query | 1 | 1280 | BEGIN |
| mysql-bin.000023 | 1280 | Query | 1 | 1406 | use `zyyshop`; update zyyshop.tt set name='小二' where id=2|
| mysql-bin.000023 | 1406 | Xid | 1 | 1437 | COMMIT /* xid=3823 */ |
| mysql-bin.000023 | 1437 | Query | 1 | 1538 | drop database zyyshop |
+------------------+------+------------+-----------+-------------+------------------------------------------------------------+
通过分析，造成数据库破坏的pos点区间是介于 1437--1538 之间，只要恢复到1437前就可。
mysqlbinlog --start-position=953 --stop-position=1538 --database=zyyshop binlog.000002 | mysql -uroot -p123456 -v zyyshop
- 指定时间恢复
- 知道自己在哪个时间段误操作了
mysql> drop table tt;
@ --start-datetime="2013-11-29 13:18:54" 起始时间点
@ --stop-datetime="2013-11-29 13:21:53" 结束时间点
# mysqlbinlog --start-datetime="2013-11-29 13:18:54" --stop-datetime="2013-11-29 13:21:53" --database=zyyshop binlog.000002 | mysql -uroot -p123456 -v zyyshop
希望这篇文章能够帮助误删操作的朋友顺利恢复数据