背景:
对于MySQL的binlog的查看都是用其自带的工具mysqlbinlog进行操作的,其实还有另一个方法来操作binlog,就是Replication中的SQL线程去操作binlog,其实binlog和relaylog的格式是一样的。下面开始介绍如何用该方法进行对binlog的操作。
测试1:
---初始化: root@192.168.200.25 : aaa 03:51:38>reset master; Query OK, 0 rows affected (0.12 sec) root@192.168.200.25 : aaa 03:51:55>reset slave; Query OK, 0 rows affected (0.00 sec) root@192.168.200.25 : aaa 03:51:59>create table test_binlog(id int not null auto_increment,name varchar(10),primary key(id))
engine =innodb default charset utf8; Query OK, 0 rows affected (0.17 sec) root@192.168.200.25 : aaa 03:52:11>insert into test_binlog(name) values('a'),('b'),('c'),('d'),('e'); Query OK, 5 rows affected (0.00 sec) Records: 5 Duplicates: 0 Warnings: 0 root@192.168.200.25 : aaa 03:52:20>insert into test_binlog(name) values('aa'),('bb'),('cc'),('dd'),('ee'); Query OK, 5 rows affected (0.00 sec) Records: 5 Duplicates: 0 Warnings: 0 root@192.168.200.25 : aaa 03:52:24>insert into test_binlog(name) values('aaa'),('bbb'),('ccc'),('ddd'),('eee'); Query OK, 5 rows affected (0.00 sec) Records: 5 Duplicates: 0 Warnings: 0 ---删除数据,为了恢复: root@192.168.200.25 : aaa 03:52:28>flush logs; Query OK, 0 rows affected (0.13 sec) root@192.168.200.25 : aaa 03:53:21>drop table test_binlog; Query OK, 0 rows affected (0.08 sec)
把Binlog复制到Relaylog 目录:
root@zhoujy:/var/lib/mysql# cp /var/log/mysql/mysql-bin.000001 /var/lib/mysql/relay-bin.000001
root@zhoujy:/var/lib/mysql# chown -R mysql:mysql relay-bin.000001
修改my.cnf文件:
relay_log = slave_relay
skip-slave-start
server-id = 2 #测试例子是自己的binlog对自己恢复,根据Replication原理,需要修改其Server_id SQL线程才能进行操作
需要生成master.info,relay-log.info,slave_relay.index等Replication需要的文件。
root@192.168.200.25 : aaa 04:00:29>change master to master_host='192.168.220.25',master_user='rep',master_password='rep',
MASTER_LOG_FILE='mysql-bin.000001', MASTER_LOG_POS=120,master_port=3306; #随便change 到一个地址,目的是为了生成SQL线程
关闭MySQL并修改Relaylog相关的文件:
vi relay-log.info
---
./slave_relay.000001
4
mysql-bin.000001
120
---
修改成:
---
./relay-bin.000001 #复制过来的binlog文件
4 #开始复制的postition
mysql-bin.000001
120
---
vi slave_relay.index
---
./slave_relay.000001
---
修改成:
---
./relay-bin.000001 #复制过来的binlog文件
---
开启MySQL并查看复制的状态:
root@192.168.200.25 : aaa 04:08:04>show slave status\G;
*************************** 1. row ***************************
Slave_IO_State:
Master_Host: 192.168.220.25
Master_User: rep
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000001
Read_Master_Log_Pos: 120
Relay_Log_File: relay-bin.000001 #Relaylog 已经被替换
Relay_Log_Pos: 4
Relay_Master_Log_File: mysql-bin.000001
Slave_IO_Running: No
Slave_SQL_Running: No
Replicate_Do_DB: aaa
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: 120
Relay_Log_Space: 1203
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: NULL
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
最后启动SQL线程:
root@192.168.200.25 : aaa 04:14:58>select * from test_binlog;
ERROR 1146 (42S02): Table 'aaa.test_binlog' doesn't exist
root@192.168.200.25 : aaa 04:15:00>start slave sql_thread;
Query OK, 0 rows affected (0.00 sec)
#已经恢复:
root@192.168.200.25 : aaa 04:15:11>select * from test_binlog;
+----+------+
| id | name |
+----+------+
| 1 | a |
| 2 | b |
| 3 | c |
| 4 | d |
| 5 | e |
| 6 | aa |
| 7 | bb |
| 8 | cc |
| 9 | dd |
| 10 | ee |
| 11 | aaa |
| 12 | bbb |
| 13 | ccc |
| 14 | ddd |
| 15 | eee |
+----+------+
15 rows in set (0.00 sec)
例1结束,上面测试说明通过binlog,把其当成relaylog进行处理,成功的用SQL线程进行恢复。
测试2:
上面是对一个binlog进行恢复的,那如何对多个binlog进行恢复呢?马上来测试下:
---log1中 root@192.168.200.25 : aaa 04:57:39>create table test_binlog(id int not null auto_increment,name varchar(10),primary key(id))
engine =innodb default charset utf8; Query OK, 0 rows affected (0.17 sec) root@192.168.200.25 : aaa 04:57:47>insert into test_binlog(name) values('a'),('b'),('c'),('d'),('e'); Query OK, 5 rows affected (0.00 sec) Records: 5 Duplicates: 0 Warnings: 0 root@192.168.200.25 : aaa 04:57:52>insert into test_binlog(name) values('aa'),('bb'),('cc'),('dd'),('ee'); Query OK, 5 rows affected (0.00 sec) Records: 5 Duplicates: 0 Warnings: 0 root@192.168.200.25 : aaa 04:57:57>flush logs; Query OK, 0 rows affected (0.13 sec) ---log2中 root@192.168.200.25 : aaa 04:58:04>insert into test_binlog(name) values('aaaa'),('bbbb'),('cccc'),('dddd'),('eeee'); Query OK, 5 rows affected (0.00 sec) Records: 5 Duplicates: 0 Warnings: 0 root@192.168.200.25 : aaa 04:58:10>insert into test_binlog(name) values('aaaaa'),('bbbbb'),('ccccc'),('ddddd'),('eeeee'); Query OK, 5 rows affected (0.00 sec) Records: 5 Duplicates: 0 Warnings: 0 root@192.168.200.25 : aaa 04:58:15>flush logs; Query OK, 0 rows affected (0.12 sec) ---log3中 root@192.168.200.25 : aaa 04:58:19>insert into test_binlog(name) values('Aaaaaa'),('Bbbbbb'),('Cccccc'),('Dddddd'),('Eeeeee'); Query OK, 5 rows affected (0.00 sec) Records: 5 Duplicates: 0 Warnings: 0 root@192.168.200.25 : aaa 04:58:23>use test; Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -A ---切换当前数据库,test下面插入10行 Database changed root@192.168.200.25 : test 04:58:29>insert into aaa.test_binlog(name) values('A'),('B'),('C'),('D'),('E'); Query OK, 5 rows affected (0.00 sec) Records: 5 Duplicates: 0 Warnings: 0 root@192.168.200.25 : test 04:58:33>insert into aaa.test_binlog(name) values('AA'),('BB'),('CC'),('DD'),('EE'); Query OK, 5 rows affected (0.00 sec) Records: 5 Duplicates: 0 Warnings: 0 ---切换当前数据库 root@192.168.200.25 : test 05:34:09>use aaa 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 root@192.168.200.25 : aaa 05:34:19>insert into aaa.test_binlog(name) values('AAAAAA'),('BBBBBBB'),('CCCCCCC'),('DDDDDDD'),('EEEEEEE'); Query OK, 5 rows affected (0.05 sec) Records: 5 Duplicates: 0 Warnings: 0 root@192.168.200.25 : aaa 05:34:40>select * from test_binlog; +----+---------+ | id | name | +----+---------+ | 1 | a | | 2 | b | | 3 | c | | 4 | d | | 5 | e | | 6 | aa | | 7 | bb | | 8 | cc | | 9 | dd | | 10 | ee | | 11 | aaaa | | 12 | bbbb | | 13 | cccc | | 14 | dddd | | 15 | eeee | | 16 | aaaaa | | 17 | bbbbb | | 18 | ccccc | | 19 | ddddd | | 20 | eeeee | | 21 | Aaaaaa | | 22 | Bbbbbb | | 23 | Cccccc | | 24 | Dddddd | | 25 | Eeeeee | | 26 | A | | 27 | B | | 28 | C | | 29 | D | | 30 | E | | 31 | AA | | 32 | BB | | 33 | CC | | 34 | DD | | 35 | EE | | 36 | AAAAAA | | 37 | BBBBBBB | | 38 | CCCCCCC | | 39 | DDDDDDD | | 40 | EEEEEEE | +----+---------+ 40 rows in set (0.00 sec)
按照例1中的步骤操作,复制Binlog:
cp mysql-bin.000001 /var/lib/mysql/relay-bin.000001
cp mysql-bin.000002 /var/lib/mysql/relay-bin.000002
cp mysql-bin.000003 /var/lib/mysql/relay-bin.000003
chown -R mysql:mysql relay-bin.00000*
修改my.cnf文件:
server-id = 12
relay_log = slave_relay
skip-slave-start
replicate_do_db = aaa
需要生成master.info,relay-log.info,slave_relay.index等Replication需要的文件。
change master to master_host='192.168.220.25',master_user='rep',master_password='rep',MASTER_LOG_FILE='mysql-bin.000001',
MASTER_LOG_POS=120,master_port=3306;
关闭MySQL并修改Relaylog相关的文件:
vi relay-log.info 修改成:
---
./relay-bin.000001
4
mysql-bin.000001
120
---
vi slave_relay.index 修改成,这里和例1不同
---
./relay-bin.000001
./relay-bin.000002
./relay-bin.000003
---
开启MySQL并查看复制的状态:
root@192.168.200.25 : aaa 05:38:04>show slave status\G;
*************************** 1. row ***************************
Slave_IO_State:
Master_Host: 192.168.220.25
Master_User: rep
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000001
Read_Master_Log_Pos: 120
Relay_Log_File: relay-bin.000001 #Relaylog 已经被替换
Relay_Log_Pos: 4
Relay_Master_Log_File: mysql-bin.000001
Slave_IO_Running: No
Slave_SQL_Running: No
Replicate_Do_DB: aaa
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: 120
Relay_Log_Space: 2889
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: NULL
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
1 row in set (0.06 sec)
最后启动SQL线程:
root@192.168.200.25 : aaa 05:44:11>select * from test_binlog;
ERROR 1146 (42S02): Table 'aaa.test_binlog' doesn't exist
root@192.168.200.25 : aaa 05:44:18>start slave sql_thread;
Query OK, 0 rows affected (0.00 sec)
root@192.168.200.25 : aaa 05:44:29>select * from test_binlog;
+----+---------+
| id | name |
+----+---------+
| 1 | a |
| 2 | b |
| 3 | c |
| 4 | d |
| 5 | e |
| 6 | aa |
| 7 | bb |
| 8 | cc |
| 9 | dd |
| 10 | ee |
| 11 | aaaa |
| 12 | bbbb |
| 13 | cccc |
| 14 | dddd |
| 15 | eeee |
| 16 | aaaaa |
| 17 | bbbbb |
| 18 | ccccc |
| 19 | ddddd |
| 20 | eeeee |
| 21 | Aaaaaa |
| 22 | Bbbbbb |
| 23 | Cccccc |
| 24 | Dddddd |
| 25 | Eeeeee |
| 36 | AAAAAA |
| 37 | BBBBBBB |
| 38 | CCCCCCC |
| 39 | DDDDDDD |
| 40 | EEEEEEE |
+----+---------+
30 rows in set (0.01 sec)
这里看到可以正常的恢复了,但是数据不对,少了10行(26~35行)。为什么少了?这里大家应该都很清楚了,因为是在初始化的时候有10行数据是在test数据库下面插入的,而在配置文件中只复制aaa数据库下的操作记录(replicate_do_db = aaa)。这也是通过Relaylog恢复的一个优点。
总结:
上面的测试在5.1到5.1 和 5.1到5.5的操作都没有问题,所以通过本文介绍的方法去操作Binlog,更有灵活性,可以随时进行stop、start slave操作;通过测试了解到,在用binlog进行增量备份的场景下,使用该方法更有效直接的进行恢复,比本身的mysqlbinlog 更有效;也可以解决mysqlbinlog的一些问题:
(*) Max_allowed_packet问题
(*) 恼人的Blob/Binary/text字段问题
(*) 特殊字符的转义问题
(*) 没有"断点恢复":执行出错后,没有足够的报错,也很难从失败的地方继续恢复