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 -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，开始建表，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 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=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-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: 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]#