binlog之五：mysqlbinlog解析binlog乱码问题解密

发现MySQL库的binlog日志出来都是乱码，如下所示： 
BINLOG ’ 
IXZqVhNIAAAALQAAAGcBAAAAAHoAAAAAAAEABHRlc3QAAno0AAEDAABUOcnY 
IXZqVh5IAAAAKAAAAI8BAAAAAHoAAAAAAAEAAgAB//4BAAAAcu+UpA==，如果强行用-v出来也得不到具体执行的sql语句，这个问题困扰了很近，今天深入研究才发现核心问题所在。

---

1，binlog日志的困扰，先看下日志格式

mysql> show variables like '%binlog%';
+-----------------------------------------+----------------------+
| Variable_name                           | Value                |
+-----------------------------------------+----------------------+
| binlog_cache_size                       | 1048576              |
| binlog_checksum                         | CRC32                |
| binlog_direct_non_transactional_updates | OFF                  |
| binlog_format                           | MIXED                |
| binlog_max_flush_queue_time             | 0                    |
| binlog_order_commits                    | ON                   |
| binlog_row_image                        | FULL                 |
| binlog_rows_query_log_events            | OFF                  |
| binlog_stmt_cache_size                  | 32768                |
| innodb_api_enable_binlog                | OFF                  |
| innodb_locks_unsafe_for_binlog          | OFF                  |
| max_binlog_cache_size                   | 18446744073709547520 |
| max_binlog_size                         | 1073741824           |
| max_binlog_stmt_cache_size              | 18446744073709547520 |
| sync_binlog                             | 1                    |
+-----------------------------------------+----------------------+
15 rows in set (0.01 sec)

mysql> 

日志格式是MIXED的，这个表示一些特殊的uuid以及now()之类会记录成row，其它的仍然是记录sql模式。

---

2，测试例子：

mysql> 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

Database changed
mysql> create table z4 select 1 as a;
Query OK, 1 row affected (0.02 sec)
Records: 1  Duplicates: 0  Warnings: 0

mysql> insert into z4 select 2;
Query OK, 1 row affected (0.00 sec)
Records: 1  Duplicates: 0  Warnings: 0

mysql> 

---

3，查看binlog，打开是乱码模式，看不到执行的sql语句，如下所示

[root@mysql5.6.12 binlog_new]# ll
总用量 32
-rw-rw----. 1 mysql mysql   143 12月 10 21:09 mysql-bin.000001
-rw-rw----. 1 mysql mysql 17549 12月 11 15:06 mysql-bin.000002
-rw-rw----. 1 mysql mysql   618 12月 11 15:07 mysql-bin.000003
-rw-rw----. 1 mysql mysql   135 12月 11 15:06 mysql-bin.index
[root@mysql5.6.12 binlog_new]# /usr/local/mysql/bin/mysqlbinlog mysql-bin.000003
/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=1*/;
/*!40019 SET @@session.max_insert_delayed_threads=0*/;
/*!50003 SET @OLD_COMPLETION_TYPE=@@COMPLETION_TYPE,COMPLETION_TYPE=0*/;
DELIMITER /*!*/;
# at 4
#151211 15:06:46 server id 72  end_log_pos 120 CRC32 0x9961ff72     Start: binlog v 4, server v 5.6.12-log created 151211 15:06:46
# Warning: this binlog is either in use or was not closed properly.
BINLOG '
BnZqVg9IAAAAdAAAAHgAAAABAAQANS42LjEyLWxvZwAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAEzgNAAgAEgAEBAQEEgAAXAAEGggAAAAICAgCAAAACgoKGRkAAXL/
YZk=
'/*!*/;
# at 120
#151211 15:07:13 server id 72  end_log_pos 192 CRC32 0x3ea43b0e     Query   thread_id=732   exec_time=0 error_code=0
SET TIMESTAMP=1449817633/*!*/;
SET @@session.pseudo_thread_id=732/*!*/;
SET @@session.foreign_key_checks=1, @@session.sql_auto_is_null=0, @@session.unique_checks=1, @@session.autocommit=1/*!*/;
SET @@session.sql_mode=1075838976/*!*/;
SET @@session.auto_increment_increment=1, @@session.auto_increment_offset=1/*!*/;
/*!\C utf8mb4 *//*!*/;
SET @@session.character_set_client=45,@@session.collation_connection=45,@@session.collation_server=45/*!*/;
SET @@session.lc_time_names=0/*!*/;
SET @@session.collation_database=DEFAULT/*!*/;
BEGIN
/*!*/;
# at 192
#151211 15:07:13 server id 72  end_log_pos 314 CRC32 0xcaec51ae     Query   thread_id=732   exec_time=0 error_code=0
use `test`/*!*/;
SET TIMESTAMP=1449817633/*!*/;
CREATE TABLE `z4` (
  `a` int(1) NOT NULL DEFAULT '0'
)
/*!*/;
# at 314
#151211 15:07:13 server id 72  end_log_pos 359 CRC32 0xd8c93954     Table_map: `test`.`z4` mapped to number 122
# at 359
#151211 15:07:13 server id 72  end_log_pos 399 CRC32 0xa494ef72     Write_rows: table id 122 flags: STMT_END_F

BINLOG '
IXZqVhNIAAAALQAAAGcBAAAAAHoAAAAAAAEABHRlc3QAAno0AAEDAABUOcnY
IXZqVh5IAAAAKAAAAI8BAAAAAHoAAAAAAAEAAgAB//4BAAAAcu+UpA==
'/*!*/;
# at 399
#151211 15:07:13 server id 72  end_log_pos 430 CRC32 0xd1ab5b55     Xid = 6908
COMMIT/*!*/;
# at 430
#151211 15:07:20 server id 72  end_log_pos 502 CRC32 0xdfc3212d     Query   thread_id=732   exec_time=0 error_code=0
SET TIMESTAMP=1449817640/*!*/;
BEGIN
/*!*/;
# at 502
#151211 15:07:20 server id 72  end_log_pos 547 CRC32 0xc59aab0e     Table_map: `test`.`z4` mapped to number 122
# at 547
#151211 15:07:20 server id 72  end_log_pos 587 CRC32 0x648b02a4     Write_rows: table id 122 flags: STMT_END_F

BINLOG '
KHZqVhNIAAAALQAAACMCAAAAAHoAAAAAAAEABHRlc3QAAno0AAEDAAAOq5rF
KHZqVh5IAAAAKAAAAEsCAAAAAHoAAAAAAAEAAgAB//4CAAAApAKLZA==
'/*!*/;
# at 587
#151211 15:07:20 server id 72  end_log_pos 618 CRC32 0x9b35600a     Xid = 6915
COMMIT/*!*/;
DELIMITER ;
# End of log file
ROLLBACK /* added by mysqlbinlog */;
/*!50003 SET COMPLETION_TYPE=@OLD_COMPLETION_TYPE*/;
/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=0*/;
[root@mysql5.6.12 binlog_new]# 

PS：大家看到/usr/local/mysql/bin/mysqlbinlog mysql-bin.000003解析出来的都是KHZqVhNIAAAALQAAACMCAAAAAHoAAAA这样的乱码格式。

---

4，google，得知可以用–base64-output=DECODE-ROWS -v查看出来sql语句，如下所示

[root@mysql5.6.12 binlog_new]# /usr/local/mysql/bin/mysqlbinlog --base64-output=DECODE-ROWS -v mysql-bin.000003
/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=1*/;
/*!40019 SET @@session.max_insert_delayed_threads=0*/;
/*!50003 SET @OLD_COMPLETION_TYPE=@@COMPLETION_TYPE,COMPLETION_TYPE=0*/;
DELIMITER /*!*/;
# at 4
#151211 15:06:46 server id 72  end_log_pos 120 CRC32 0x9961ff72     Start: binlog v 4, server v 5.6.12-log created 151211 15:06:46
# Warning: this binlog is either in use or was not closed properly.
# at 120
#151211 15:07:13 server id 72  end_log_pos 192 CRC32 0x3ea43b0e     Query   thread_id=732   exec_time=0 error_code=0
SET TIMESTAMP=1449817633/*!*/;
SET @@session.pseudo_thread_id=732/*!*/;
SET @@session.foreign_key_checks=1, @@session.sql_auto_is_null=0, @@session.unique_checks=1, @@session.autocommit=1/*!*/;
SET @@session.sql_mode=1075838976/*!*/;
SET @@session.auto_increment_increment=1, @@session.auto_increment_offset=1/*!*/;
/*!\C utf8mb4 *//*!*/;
SET @@session.character_set_client=45,@@session.collation_connection=45,@@session.collation_server=45/*!*/;
SET @@session.lc_time_names=0/*!*/;
SET @@session.collation_database=DEFAULT/*!*/;
BEGIN
/*!*/;
# at 192
#151211 15:07:13 server id 72  end_log_pos 314 CRC32 0xcaec51ae     Query   thread_id=732   exec_time=0 error_code=0
use `test`/*!*/;
SET TIMESTAMP=1449817633/*!*/;
CREATE TABLE `z4` (
  `a` int(1) NOT NULL DEFAULT '0'
)
/*!*/;
# at 314
#151211 15:07:13 server id 72  end_log_pos 359 CRC32 0xd8c93954     Table_map: `test`.`z4` mapped to number 122
# at 359
#151211 15:07:13 server id 72  end_log_pos 399 CRC32 0xa494ef72     Write_rows: table id 122 flags: STMT_END_F
### INSERT INTO `test`.`z4`
### SET
###   @1=1
# at 399
#151211 15:07:13 server id 72  end_log_pos 430 CRC32 0xd1ab5b55     Xid = 6908
COMMIT/*!*/;
# at 430
#151211 15:07:20 server id 72  end_log_pos 502 CRC32 0xdfc3212d     Query   thread_id=732   exec_time=0 error_code=0
SET TIMESTAMP=1449817640/*!*/;
BEGIN
/*!*/;
# at 502
#151211 15:07:20 server id 72  end_log_pos 547 CRC32 0xc59aab0e     Table_map: `test`.`z4` mapped to number 122
# at 547
#151211 15:07:20 server id 72  end_log_pos 587 CRC32 0x648b02a4     Write_rows: table id 122 flags: STMT_END_F
### INSERT INTO `test`.`z4`
### SET
###   @1=2
# at 587
#151211 15:07:20 server id 72  end_log_pos 618 CRC32 0x9b35600a     Xid = 6915
COMMIT/*!*/;
DELIMITER ;
# End of log file
ROLLBACK /* added by mysqlbinlog */;
/*!50003 SET COMPLETION_TYPE=@OLD_COMPLETION_TYPE*/;
/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=0*/;
[root@mysql5.6.12 binlog_new]# 

确实可以看到sql语句，不过都是row模式的，如下所示：

### INSERT INTO `test`.`z4`
### SET
###   @1=2
# at 587

看到不到应用程序或者客户端执行的真正sql语句，这样也不利于进行业务分析数据分析，无助于对程序的优化。

---

5，问题分析

这样binlog日志格式MIXED都录制为乱码，那我将换成STATEMENT格式看看是否会持续乱码？，修改完my.cnf后，重启mysql数据库，开始建表测试，但是报错如下：

mysql> create table z3 select 1 as a;
ERROR 1665 (HY000): Cannot execute statement: impossible to write to binary log since BINLOG_FORMAT = STATEMENT and at least one table uses a storage engine limited to row-based logging. InnoDB is limited to row-logging when transaction isolation level is READ COMMITTED or READ UNCOMMITTED.
mysql> 

问题发现了，看到问题贺新郎，隔离级别太低了，我的默认隔离级别是READ-COMMITTED，所以导致binlog记录的必须都是row模式，解析出来的是乱码，强行用-v显示出来也是row模式，所以我将隔离级别升级为REPEATABLE-READ的话，就会有row格式也会有statement格式了。接下来为了用2个小实例来验证我的判断：

---

4.1 REPEATABLE-READ和STATEMENT测试结果

**所以我将隔离级别升级为REPEATABLE-READ，binlog设置为binlog_format=STATEMENT 
如下所示：**

# Set the default transaction isolation level. Levels available are:
# READ-UNCOMMITTED, READ-COMMITTED, REPEATABLE-READ, SERIALIZABLE
transaction_isolation = REPEATABLE-READ
binlog_format=STATEMENT

然后重启mysql，看binlog的记录形式是啥样的，如下所示：

BEGIN
/*!*/;
# at 219
# at 251
#151211 16:15:02 server id 72  end_log_pos 251 CRC32 0x4ea440db     Intvar
SET INSERT_ID=10550/*!*/;
#151211 16:15:02 server id 72  end_log_pos 435 CRC32 0xa37c5f2d     Query   thread_id=1 exec_time=0 error_code=0
use `parking_db`/*!*/;
SET TIMESTAMP=1449821702/*!*/;
INSERT INTO access_log.access_log VALUES(NULL,CONNECTION_ID(),NOW(),USER(),CURRENT_USER())
/*!*/;
# at 435
#151211 16:15:02 server id 72  end_log_pos 466 CRC32 0x2970e89a     Xid = 3
COMMIT/*!*/;
# at 466
#151211 16:16:22 server id 72  end_log_pos 569 CRC32 0xbe43b367     Query   thread_id=2 exec_time=0 error_code=0
use `test`/*!*/;
SET TIMESTAMP=1449821782/*!*/;
create table z4 select 1 as a
/*!*/;
# at 569
#151211 16:16:32 server id 72  end_log_pos 648 CRC32 0x69b2383c     Query   thread_id=2 exec_time=0 error_code=0
SET TIMESTAMP=1449821792/*!*/;
BEGIN
/*!*/;
# at 648
#151211 16:16:32 server id 72  end_log_pos 745 CRC32 0xcd1721a4     Query   thread_id=2 exec_time=0 error_code=0
SET TIMESTAMP=1449821792/*!*/;
insert into z4 select 2
/*!*/;
# at 745
#151211 16:16:32 server id 72  end_log_pos 776 CRC32 0xfc0dcfc4     Xid = 70
COMMIT/*!*/;
DELIMITER ;
# End of log file
ROLLBACK /* added by mysqlbinlog */;
/*!50003 SET COMPLETION_TYPE=@OLD_COMPLETION_TYPE*/;
/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=0*/;
[root@mysql5.6.12 binlog_new]# 

看到有类似的INSERT INTO access_log.access_log VALUES(NULL,CONNECTION_ID(),NOW(),USER(),CURRENT_USER())这里的一些函数最好用row模式，因为主从复制的时候，uuid已经now()等会造成时间延迟，故而为了数据一致性，statement格式不是最佳选择。

---

4.2 REPEATABLE-READ和MIXED测试结果

my.cnf里面修改设置：

transaction_isolation = REPEATABLE-READ
binlog_format=MIXED

重启mysql数据库后，录入测试数据：

mysql> insert into z4 select 3;
Query OK, 1 row affected (0.00 sec)
Records: 1  Duplicates: 0  Warnings: 0

mysql> exit

查看binlog数据，会看到insert into z4 select 3这条sql记录，表明在mixed模式下，解析出来的sql是正常的，有些now()已经uuid的直接解析成row格式了，如下所示：

[root@mysql5.6.12 binlog_new]# /usr/local/mysql/bin/mysqlbinlog --base64-output=DECODE-ROWS -v mysql-bin.000007
...
# at 274
#151211 16:21:02 server id 72  end_log_pos 368 CRC32 0x156a1c51     Write_rows: table id 70 flags: STMT_END_F
### INSERT INTO `access_log`.`access_log`
### SET
###   @1=10551
###   @2=1
###   @3=1449822062
###   @4='park_user@192.168.121.243'
###   @5='park_user@192.168.%'
# at 368
#151211 16:21:02 server id 72  end_log_pos 399 CRC32 0x8254defe     Xid = 3
COMMIT/*!*/;
# at 399
#151211 16:21:25 server id 72  end_log_pos 478 CRC32 0xe252f5c7     Query   thread_id=2 exec_time=0 error_code=0
SET TIMESTAMP=1449822085/*!*/;
BEGIN
/*!*/;
# at 478
#151211 16:21:25 server id 72  end_log_pos 575 CRC32 0x34308ad6     Query   thread_id=2 exec_time=0 error_code=0
use `test`/*!*/;
SET TIMESTAMP=1449822085/*!*/;
insert into z4 select 3
/*!*/;
# at 575
#151211 16:21:25 server id 72  end_log_pos 606 CRC32 0x67c460eb     Xid = 61
COMMIT/*!*/;
DELIMITER ;
# End of log file
ROLLBACK /* added by mysqlbinlog */;
/*!50003 SET COMPLETION_TYPE=@OLD_COMPLETION_TYPE*/;
/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=0*/;
[root@mysql5.6.12 binlog_new]#