MySQL 利用SQL线程对Binlog操作

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

更多信息：
http://www.orczhou.com/index.php/2013/11/use-mysql-replication-to-recove-binlog/
http://blog.itpub.net/22664653/viewspace-775778/