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 namesYou can turn off this feature to get a quicker startup with -ADatabase changedmysql> create table z4 select 1 as a;Query OK, 1 row affected (0.02 sec)Records: 1 Duplicates: 0 Warnings: 0mysql> insert into z4 select 2;Query OK, 1 row affected (0.00 sec)Records: 1 Duplicates: 0 Warnings: 0mysql> blog为csdn博主黄杉(mchdba)所有，原地址为：http://blog.csdn.net/mchdba/article/details/50300035，谢绝转载。
3，查看binlog，打开是乱码模式，看不到执行的sql语句，如下所示
[[email protected] 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[[email protected] 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 'BnZqVg9IAAAAdAAAAHgAAAABAAQANS42LjEyLWxvZwAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAEzgNAAgAEgAEBAQEEgAAXAAEGggAAAAICAgCAAAACgoKGRkAAXL/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=0SET 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=0use `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_FBINLOG 'IXZqVhNIAAAALQAAAGcBAAAAAHoAAAAAAAEABHRlc3QAAno0AAEDAABUOcnYIXZqVh5IAAAAKAAAAI8BAAAAAHoAAAAAAAEAAgAB//4BAAAAcu+UpA=='/*!*/;# at 399#151211 15:07:13 server id 72 end_log_pos 430 CRC32 0xd1ab5b55 Xid = 6908COMMIT/*!*/;# at 430#151211 15:07:20 server id 72 end_log_pos 502 CRC32 0xdfc3212d Query thread_id=732 exec_time=0 error_code=0SET 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_FBINLOG 'KHZqVhNIAAAALQAAACMCAAAAAHoAAAAAAAEABHRlc3QAAno0AAEDAAAOq5rFKHZqVh5IAAAAKAAAAEsCAAAAAHoAAAAAAAEAAgAB//4CAAAApAKLZA=='/*!*/;# at 587#151211 15:07:20 server id 72 end_log_pos 618 CRC32 0x9b35600a Xid = 6915COMMIT/*!*/;DELIMITER ;# End of log fileROLLBACK /* added by mysqlbinlog */;/*!50003 SET [email protected]_COMPLETION_TYPE*/;/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=0*/;[[email protected] 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
[[email protected].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=0SET 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=0use `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 = 6908COMMIT/*!*/;# at 430#151211 15:07:20 server id 72 end_log_pos 502 CRC32 0xdfc3212d Query thread_id=732 exec_time=0 error_code=0SET 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 = 6915COMMIT/*!*/;DELIMITER ;# End of log fileROLLBACK /* added by mysqlbinlog */;/*!50003 SET [email protected]_COMPLETION_TYPE*/;/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=0*/;[[email protected].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, SERIALIZABLEtransaction_isolation = REPEATABLE-READbinlog_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 IntvarSET 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=0use `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 = 3COMMIT/*!*/;# at 466#151211 16:16:22 server id 72 end_log_pos 569 CRC32 0xbe43b367 Query thread_id=2 exec_time=0 error_code=0use `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=0SET 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=0SET TIMESTAMP=1449821792/*!*/;insert into z4 select 2/*!*/;# at 745#151211 16:16:32 server id 72 end_log_pos 776 CRC32 0xfc0dcfc4 Xid = 70COMMIT/*!*/;DELIMITER ;# End of log fileROLLBACK /* added by mysqlbinlog */;/*!50003 SET [email protected]_COMPLETION_TYPE*/;/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=0*/;[[email protected] 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-READbinlog_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: 0mysql> 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：
[[email protected].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### @[email protected]'### @[email protected]%'# at 368#151211 16:21:02 server id 72 end_log_pos 399 CRC32 0x8254defe Xid = 3COMMIT/*!*/;# at 399#151211 16:21:25 server id 72 end_log_pos 478 CRC32 0xe252f5c7 Query thread_id=2 exec_time=0 error_code=0SET 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=0use `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 = 61COMMIT/*!*/;DELIMITER ;# End of log fileROLLBACK /* added by mysqlbinlog */;/*!50003 SET [email protected]_COMPLETION_TYPE*/;/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=0*/;[[email protected].6.12 binlog_new]#