知识点
1.binlog 日志组成分析
2.binlog日志复制的几种复制模式
3.now()和sysdate()在语义化复制要注意的点
binary log日志简介
查看日志格式
show variables like 'binlog_format';
+---------------+-----------+ | Variable_name | Value | +---------------+-----------+ | binlog_format | STATEMENT | +---------------+-----------+
二进制日志的内容结构
二进制日志的内容由以下三部分组成
(1) 文件头 ：格式描述事件
(2)文件主体:二进制日志事件
(3)文件尾:日志轮换事件
格式描述事件包含的内容:服务器版本,通用头长度,文件状态信息
binlog事件体：日志文件,位置,事件类型(query,xid,user_var),服务器id,结束位置,详细语句信息
文件尾:事件轮换事件
什么时候轮换?
重启数据库
binlog文件达到最大尺寸
flush logs 操作
异常轮换
奔溃或者非正常关闭(kill杀进程)数据库时,轮换日志表示未正常的关闭(没有轮换记录)
用户数据库奔溃的系统自动修复,或者dba干扰重放
mysql> show binary logs;
+------------------+-----------+ | Log_name | File_size | +------------------+-----------+ | mysql-bin.000001 | 19730 | | mysql-bin.000002 | 765307 | | mysql-bin.000003 | 624 | | mysql-bin.000004 | 327 | | mysql-bin.000005 | 409 | +------------------+-----------+ 5 rows in set (0.00 sec) mysql> show binlog events in 'mysql-bin.000005'; +------------------+-----+-------------+-----------+-------------+--------------------------------------------+ | Log_name | Pos | Event_type | Server_id | End_log_pos | Info | +------------------+-----+-------------+-----------+-------------+--------------------------------------------+ | mysql-bin.000005 | 4 | Format_desc | 250 | 106 | Server ver: 5.1.73-log, Binlog ver: 4 | | mysql-bin.000005 | 106 | Query | 250 | 207 | use `hk`; insert into test values(4,now()) | | mysql-bin.000005 | 207 | Query | 250 | 308 | use `hk`; insert into test values(5,now()) | | mysql-bin.000005 | 308 | Query | 250 | 409 | use `hk`; insert into test values(6,now()) | +------------------+-----+-------------+-----------+-------------+--------------------------------------------+ mysql> flush logs; Query OK, 0 rows affected (0.02 sec) mysql> show binary logs; +------------------+-----------+ | Log_name | File_size | +------------------+-----------+ | mysql-bin.000001 | 19730 | | mysql-bin.000002 | 765307 | | mysql-bin.000003 | 624 | | mysql-bin.000004 | 327 | | mysql-bin.000005 | 452 | | mysql-bin.000006 | 106 | +------------------+-----------+ mysql> show binlog events in 'mysql-bin.000005'; +------------------+-----+-------------+-----------+-------------+--------------------------------------------+ | Log_name | Pos | Event_type | Server_id | End_log_pos | Info | +------------------+-----+-------------+-----------+-------------+--------------------------------------------+ | mysql-bin.000005 | 4 | Format_desc | 250 | 106 | Server ver: 5.1.73-log, Binlog ver: 4 | | mysql-bin.000005 | 106 | Query | 250 | 207 | use `hk`; insert into test values(4,now()) | | mysql-bin.000005 | 207 | Query | 250 | 308 | use `hk`; insert into test values(5,now()) | | mysql-bin.000005 | 308 | Query | 250 | 409 | use `hk`; insert into test values(6,now()) | | mysql-bin.000005 | 409 | Rotate | 250 | 452 | mysql-bin.000006;pos=4 | +------------------+-----+-------------+-----------+-------------+--------------------------------------------+ 5 rows in set (0.00 sec) mysql> show binlog events in 'mysql-bin.000006'; +------------------+-----+-------------+-----------+-------------+---------------------------------------+ | Log_name | Pos | Event_type | Server_id | End_log_pos | Info | +------------------+-----+-------------+-----------+-------------+---------------------------------------+ | mysql-bin.000006 | 4 | Format_desc | 250 | 106 | Server ver: 5.1.73-log, Binlog ver: 4 | +------------------+-----+-------------+-----------+-------------+---------------------------------------+ 1 row in set (0.00 sec) ps -ef|grep mysql mysql 2759 1 0 Feb07 ? 00:00:16 /usr/libexec/mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql --log-error=/var/log/mysqld.log --pid-file=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock root 5161 4530 0 08:06 pts/0 00:00:00 grep mysql [root@centos1 ~]# kill -9 2759 [root@centos1 ~]# service mysqld status; mysqld 已死，但 pid 文件仍存 [root@centos1 log]# service mysqld start 正在启动 mysqld：
mysql> show binary logs; +------------------+-----------+ | Log_name | File_size | +------------------+-----------+ | mysql-bin.000001 | 19730 | | mysql-bin.000002 | 765307 | | mysql-bin.000003 | 624 | | mysql-bin.000004 | 327 | | mysql-bin.000005 | 452 | | mysql-bin.000006 | 106 | | mysql-bin.000007 | 106 | +------------------+-----------+ 7 rows in set (0.00 sec) mysql> show binlog events in 'mysql-bin.000006'; +------------------+-----+-------------+-----------+-------------+---------------------------------------+ | Log_name | Pos | Event_type | Server_id | End_log_pos | Info | +------------------+-----+-------------+-----------+-------------+---------------------------------------+ | mysql-bin.000006 | 4 | Format_desc | 250 | 106 | Server ver: 5.1.73-log, Binlog ver: 4 | +------------------+-----+-------------+-----------+-------------+---------------------------------------+ 1 row in set (0.00 sec) mysql> show binlog events in 'mysql-bin.000007'; +------------------+-----+-------------+-----------+-------------+---------------------------------------+ | Log_name | Pos | Event_type | Server_id | End_log_pos | Info | +------------------+-----+-------------+-----------+-------------+---------------------------------------+ | mysql-bin.000007 | 4 | Format_desc | 250 | 106 | Server ver: 5.1.73-log, Binlog ver: 4 | +------------------+-----+-------------+-----------+-------------+---------------------------------------+ mysql-bin.000006 没有轮换事件
mysql二进制的复制有3中格式
1.基于语句的复制
配置选项 :binlog_format=STAEMENT
特点:相对落后,把主库的语句放到从库再执行一次,速度较慢,无法保证所有语句都正确复制,但是二进制日志相对较小
2.基于行的复制
配置选项 : binlog_format=row
特点:将主库的改动记为二进制日志的一行,保存的是物理的更新数据,更加方便,速度相对较快,保证所有语句都能正确复制
但二进制日志文件相对较大
3.混合类型
binlog_format=mixed
大多情况下是statement 格式,只有特定情况下是row 格式
在statement下
在slave库
stop slave io_thread; show slave status\G Connect_Retry: 60 Master_Log_File: mysql-bin.000008 Read_Master_Log_Pos: 120 Relay_Log_File: mysqld-relay-bin.000019 Relay_Log_Pos: 283 Relay_Master_Log_File: mysql-bin.000008 Slave_IO_Running: No Slave_SQL_Running: Yes 在主库 mysql> select * from test; +----+---------------------+ | id | time | +----+---------------------+ | 1 | 2017-02-04 10:04:12 | | 2 | 2017-02-04 13:53:35 | | 3 | 2017-02-08 19:46:49 | | 4 | 2017-02-08 20:34:49 | | 5 | 2017-02-09 09:34:42 | | 6 | 2017-02-09 10:08:48 | | 7 | 2017-02-09 10:18:06 | | 8 | 2017-02-09 17:35:10 | +----+---------------------+ mysql> flush logs; Query OK, 0 rows affected (0.05 sec) mysql> show binary logs; +------------------+-----------+ | Log_name | File_size | +------------------+-----------+ | mysql-bin.000001 | 143 | | mysql-bin.000002 | 367 | | mysql-bin.000003 | 120 | | mysql-bin.000004 | 677 | | mysql-bin.000005 | 367 | | mysql-bin.000006 | 619 | | mysql-bin.000007 | 591 | | mysql-bin.000008 | 167 | | mysql-bin.000009 | 120 | +------------------+-----------+ 9 rows in set (0.00 sec) mysql> insert into test values(9,now()); Query OK, 1 row affected (0.00 sec) mysql> insert into test values(10,sysdate()); Query OK, 1 row affected, 1 warning (0.00 sec) mysql> select * from test; +----+---------------------+ | id | time | +----+---------------------+ | 1 | 2017-02-04 10:04:12 | | 2 | 2017-02-04 13:53:35 | | 3 | 2017-02-08 19:46:49 | | 4 | 2017-02-08 20:34:49 | | 5 | 2017-02-09 09:34:42 | | 6 | 2017-02-09 10:08:48 | | 7 | 2017-02-09 10:18:06 | | 8 | 2017-02-09 17:35:10 | | 9 | 2017-02-10 09:21:17 | | 10 | 2017-02-10 09:21:33 |
因为从库的io进程没开
所以没有把主库的二进制日志取到relay log里,slave里自然没有记录
现在slave开启io_thread ;
start slave io_thread;
在slave
mysql> select * from test; +----+---------------------+ | id | time | +----+---------------------+ | 1 | 2017-02-04 10:04:12 | | 2 | 2017-02-04 13:53:35 | | 3 | 2017-02-08 19:46:49 | | 4 | 2017-02-08 20:34:49 | | 5 | 2017-02-09 09:34:42 | | 6 | 2017-02-09 10:09:40 | | 7 | 2017-02-09 10:18:06 | | 8 | 2017-02-09 17:35:10 | +----+---------------------+ 8 rows in set (0.01 sec) mysql> start slave io_thread; Query OK, 0 rows affected (0.01 sec) mysql> select * from test; +----+---------------------+ | id | time | +----+---------------------+ | 1 | 2017-02-04 10:04:12 | | 2 | 2017-02-04 13:53:35 | | 3 | 2017-02-08 19:46:49 | | 4 | 2017-02-08 20:34:49 | | 5 | 2017-02-09 09:34:42 | | 6 | 2017-02-09 10:09:40 | | 7 | 2017-02-09 10:18:06 | | 8 | 2017-02-09 17:35:10 | | 9 | 2017-02-10 09:21:17 | | 10 | 2017-02-10 09:24:45 | +----+---------------------+ 10 rows in set (0.00 sec)
发现只有id为9的记录和主库一样,id为10的记录有延迟,和主库不一致
在master
mysql> show binlog events in 'mysql-bin.000009'; +------------------+-----+-------------+-----------+-------------+-------------------------------------------------+ | Log_name | Pos | Event_type | Server_id | End_log_pos | Info | +------------------+-----+-------------+-----------+-------------+-------------------------------------------------+ | mysql-bin.000009 | 4 | Format_desc | 108 | 120 | Server ver: 5.6.35-log, Binlog ver: 4 | | mysql-bin.000009 | 120 | Query | 108 | 203 | BEGIN | | mysql-bin.000009 | 203 | Query | 108 | 313 | use `hk`; insert into test values(9,now()) | | mysql-bin.000009 | 313 | Xid | 108 | 344 | COMMIT /* xid=24 */ | | mysql-bin.000009 | 344 | Query | 108 | 427 | BEGIN | | mysql-bin.000009 | 427 | Query | 108 | 542 | use `hk`; insert into test values(10,sysdate()) | | mysql-bin.000009 | 542 | Xid | 108 | 573 | COMMIT /* xid=25 */ | +------------------+-----+-------------+-----------+-------------+-------------------------------------------------+
二进制日志里记录了这2次插入
到slave
show slave status\G Master_Log_File: mysql-bin.000009 Read_Master_Log_Pos: 573 Relay_Log_File: mysqld-relay-bin.000022 Relay_Log_Pos: 736 Relay_Master_Log_File: mysql-bin.000009 Slave_IO_Running: Yes Slave_SQL_Running: Yes
现在的Relay_Log_File: mysqld-relay-bin.000022
到slave的mysql外面
[root@bogon ~]# cd /var/lib/mysql [root@bogon mysql]# ll 总用量 110624 -rw-rw----. 1 mysql mysql 56 2月 8 19:44 auto.cnf drwx------. 2 mysql mysql 49 2月 4 10:03 hk -rw-rw----. 1 mysql mysql 12582912 2月 10 09:24 ibdata1 -rw-rw----. 1 mysql mysql 50331648 2月 10 09:24 ib_logfile0 -rw-rw----. 1 mysql mysql 50331648 2月 3 16:53 ib_logfile1 -rw-rw----. 1 mysql mysql 127 2月 10 09:24 master.info drwx------. 2 mysql mysql 4096 2月 3 16:53 mysql -rw-rw----. 1 mysql mysql 221 2月 10 09:24 mysqld-relay-bin.000021 -rw-rw----. 1 mysql mysql 736 2月 10 09:24 mysqld-relay-bin.000022 -rw-rw----. 1 mysql mysql 52 2月 10 09:24 mysqld-relay-bin.index srwxrwxrwx. 1 mysql mysql 0 2月 10 09:07 mysql.sock drwx------. 2 mysql mysql 4096 2月 3 16:53 performance_schema -rw-rw----. 1 mysql mysql 59 2月 10 09:24 relay-log.info