通过Maxwell实时增量抽取MySQLbinlog并通过stdout展示
下载Maxwell
解压Maxwell
修改MySQL的配置文件my.cnf
[root@hadoop000 etc]# vi my.cnf
[mysqld]
server-id = 1
binlog_format = ROWbinlog_format必须设为ROW模式，如果设为其他模式，比如binlog_format = STATEMENT，启动maxwell时会报错
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[root@hadoop001 maxwell-1.17.1]# bin/maxwell --user='maxwell' --password='maxwell' --host='127.0.0.1' --producer=stdout
Using kafka version: 1.0.0
08:57:08,194 WARN MaxwellMetrics - Metrics will not be exposed: metricsReportingType not configured.
08:57:08,521 INFO TaskManager - Stopping 0 tasks
08:57:08,521 ERROR TaskManager - cause:
com.zendesk.maxwell.MaxwellCompatibilityError: variable binlog_format must be set to 'ROW'
at com.zendesk.maxwell.MaxwellMysqlStatus.ensureVariableState(MaxwellMysqlStatus.java:42) ~[maxwell-1.17.1.jar:1.17.1]
at com.zendesk.maxwell.MaxwellMysqlStatus.ensureReplicationMysqlState(MaxwellMysqlStatus.java:70) ~[maxwell-1.17.1.jar:1.17.1]
at com.zendesk.maxwell.Maxwell.startInner(Maxwell.java:173) ~[maxwell-1.17.1.jar:1.17.1]
at com.zendesk.maxwell.Maxwell.start(Maxwell.java:156) ~[maxwell-1.17.1.jar:1.17.1]
at com.zendesk.maxwell.Maxwell.main(Maxwell.java:245) ~[maxwell-1.17.1.jar:1.17.1]
08:57:08,525 INFO TaskManager - Stopped all tasks
com.zendesk.maxwell.MaxwellCompatibilityError: variable binlog_format must be set to 'ROW'
at com.zendesk.maxwell.MaxwellMysqlStatus.ensureVariableState(MaxwellMysqlStatus.java:42)
at com.zendesk.maxwell.MaxwellMysqlStatus.ensureReplicationMysqlState(MaxwellMysqlStatus.java:70)
at com.zendesk.maxwell.Maxwell.startInner(Maxwell.java:173)
at com.zendesk.maxwell.Maxwell.start(Maxwell.java:156)
at com.zendesk.maxwell.Maxwell.main(Maxwell.java:245)启动MySQL
[mysqladmin@hadoop000 ~]$ service mysql start
Starting MySQL.... [ OK ]
[mysqladmin@hadoop000 ~]$ mysql -uroot -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.6.23-log MySQL Community Server (GPL)
Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> show variables like '%binlog%';
+-----------------------------------------+----------------------+
| Variable_name | Value |
+-----------------------------------------+----------------------+
| binlog_cache_size | 32768 |
| binlog_checksum | CRC32 |
| binlog_direct_non_transactional_updates | OFF |
| binlog_error_action | IGNORE_ERROR |
| binlog_format | ROW | //binlog_format已生效
| binlog_gtid_simple_recovery | OFF |
| 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 |
| binlogging_impossible_mode | IGNORE_ERROR |
| innodb_api_enable_binlog | OFF |
| innodb_locks_unsafe_for_binlog | ON |
| max_binlog_cache_size | 18446744073709547520 |
| max_binlog_size | 1073741824 |
| max_binlog_stmt_cache_size | 18446744073709547520 |
| simplified_binlog_gtid_recovery | OFF |
| sync_binlog | 0 |
+-----------------------------------------+----------------------+
19 rows in set (0.00 sec)在MySQL中创建maxwell库和用户
mysql> create database maxwell;
mysql> GRANT ALL on maxwell.* to 'maxwell'@'%' identified by 'maxwell';
mysql> GRANT SELECT, REPLICATION CLIENT, REPLICATION SLAVE on *.* to 'maxwell'@'%';
mysql> flush privileges; //一定记得刷新权限在MySQL中创建一个测试数据库和表
//创建一个数据库
mysql> create database hlwtest;
mysql> grant all privileges on hlwtest.* to hlw@'%' identified by '123456';
mysql> flush privileges;
mysql> use hlwtest;
Database changed
mysql> show tables;
Empty set (0.00 sec)
//建表语句
create table emp (
empno numeric(4) primary key,
ename varchar(10),
job varchar(9),
mgr numeric(4),
hiredate datetime,
sal numeric(7,2),
comm numeric(7,2),
deptno numeric(2)
);
//查看数据库中的表
mysql> show tables;
+-------------------+
| Tables_in_hlwtest |
+-------------------+
| emp |
+-------------------+
mysql> desc emp;
+----------+--------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+----------+--------------+------+-----+---------+-------+
| empno | decimal(4,0) | NO | PRI | NULL | |
| ename | varchar(10) | YES | | NULL | |
| job | varchar(9) | YES | | NULL | |
| mgr | decimal(4,0) | YES | | NULL | |
| hiredate | datetime | YES | | NULL | |
| sal | decimal(7,2) | YES | | NULL | |
| comm | decimal(7,2) | YES | | NULL | |
| deptno | decimal(2,0) | YES | | NULL | |
+----------+--------------+------+-----+---------+-------+
//导入测试数据
mysql> LOAD DATA LOCAL INFILE '/root/data/emp.txt' INTO TABLE emp FIELDS TERMINATED BY '\t' LINES TERMINATED BY '\r\n';
mysql> select * from emp;
+-------+--------+-----------+------+---------------------+----------+---------+--------+
| empno | ename | job | mgr | hiredate | sal | comm | deptno |
+-------+--------+-----------+------+---------------------+----------+---------+--------+
| 7369 | SMITH | CLERK | 7902 | 1980-12-17 00:00:00 | 800.00 | 0.00 | 20 |
| 7499 | ALLEN | SALESMAN | 7698 | 1981-02-20 00:00:00 | 1600.00 | 300.00 | 30 |
| 7521 | WARD | SALESMAN | 7698 | 1981-02-22 00:00:00 | 1250.00 | 500.00 | 30 |
| 7566 | JONES | MANAGER | 7839 | 1981-04-02 00:00:00 | 2975.00 | 0.00 | 20 |
| 7654 | MARTIN | SALESMAN | 7698 | 1981-09-28 00:00:00 | 1250.00 | 1400.00 | 30 |
| 7698 | BLAKE | MANAGER | 7839 | 1981-05-01 00:00:00 | 2850.00 | 0.00 | 30 |
| 7782 | CLARK | MANAGER | 7839 | 1981-06-09 00:00:00 | 2450.00 | 0.00 | 10 |
| 7788 | SCOTT | ANALYST | 7566 | 1987-04-19 00:00:00 | 3000.00 | 0.00 | 20 |
| 7839 | KING | PRESIDENT | 0 | 1981-11-17 00:00:00 | 5000.00 | 0.00 | 10 |
| 7844 | TURNER | SALESMAN | 7698 | 1981-09-08 00:00:00 | 1500.00 | 0.00 | 30 |
| 7876 | ADAMS | CLERK | 7788 | 1987-05-23 00:00:00 | 1100.00 | 0.00 | 20 |
| 7900 | JAMES | CLERK | 7698 | 1981-12-03 00:00:00 | 950.00 | 0.00 | 30 |
| 7902 | FORD | ANALYST | 7566 | 1981-12-03 00:00:00 | 3000.00 | 0.00 | 20 |
| 7934 | MILLER | CLERK | 7782 | 1982-01-23 00:00:00 | 1300.00 | 0.00 | 10 |
| 8888 | HIVE | PROGRAM | 7839 | 1988-01-23 00:00:00 | 10300.00 | 0.00 | NULL |
+-------+--------+-----------+------+---------------------+----------+---------+--------+启动maxwell进程，首先使用stdout模式测试一下
[root@hadoop001 maxwell-1.17.1]# bin/maxwell --user='maxwell' --password='maxwell' --host='127.0.0.1' --producer=stdout
Using kafka version: 1.0.0
19:04:48,030 WARN MaxwellMetrics - Metrics will not be exposed: metricsReportingType not configured.
19:04:48,365 INFO SchemaStoreSchema - Creating maxwell database
19:04:48,559 INFO Maxwell - Maxwell v1.17.1 is booting (StdoutProducer), starting at Position[BinlogPosition[mysql-bin.000014:5999], lastHeartbeat=0]
19:04:48,713 INFO AbstractSchemaStore - Maxwell is capturing initial schema
19:04:49,339 INFO BinlogConnectorReplicator - Setting initial binlog pos to: mysql-bin.000014:5999
19:04:49,506 INFO BinaryLogClient - Connected to 127.0.0.1:3306 at mysql-bin.000014/5999 (sid:6379, cid:10)
19:04:49,506 INFO BinlogConnectorLifecycleListener - Binlog connected.向测试表中插入一条数据
mysql> insert into emp (empno,ename,job,mgr,hiredate,sal,comm,deptno) values (6001,'SIWA','DESIGNER',7001,'2019-03-08',1000,6000,40);查看Maxwell控制台
{"database":"hlwtest","table":"emp","type":"insert","ts":1552043107,"xid":444,"commit":true,"data":{"empno":6001,"ename":"SIWA","job":"DESIGNER","mgr":7001,"hiredate":"2019-03-08 00:00:00","sal":1000.00,"comm":6000.00,"deptno":40}}再插入一条数据，查看binlog日志内容
//MySQL
mysql> update emp set sal=500 where empno=6001;
//Maxwell
{"database":"hlwtest","table":"emp","type":"update","ts":1552090904,"xid":138,"commit":true,"data":{"empno":6001,"ename":"SIWA","job":"DESIGNER","mgr":7001,"hiredate":"2019-03-08 00:00:00","sal":500.00,"comm":6000.00,"deptno":40},"old":{"sal":1000.00}}- 首先使用show binlog events的方式查看
//MySQL
mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000016 | 40967 | | | |
+------------------+----------+--------------+------------------+-------------------+
mysql> show binlog events in 'mysql-bin.000016' from 3954 limit 3;
+------------------+------+-------------+-----------+-------------+--------------------------------+
| Log_name | Pos | Event_type | Server_id | End_log_pos | Info |
+------------------+------+-------------+-----------+-------------+--------------------------------+
| mysql-bin.000016 | 3954 | Table_map | 1 | 4025 | table_id: 71 (hlwtest.emp) |
| mysql-bin.000016 | 4025 | Update_rows | 1 | 4127 | table_id: 71 flags: STMT_END_F |
| mysql-bin.000016 | 4127 | Xid | 1 | 4158 | COMMIT /* xid=138 */ |
+------------------+------+-------------+-----------+-------------+--------------------------------+- 从解析的binlog中可以看出row模式下,DML操作会记录为:TABLE_MAP_EVENT+ROW_LOG_EVENT（包括WRITE_ROWS_EVENT ，UPDATE_ROWS_EVENT，DELETE_ROWS_EVENT). 为什么一个update在ROW模式下需要分解成两个event：一个Table_map，一个Update_rows。我们想象一下，一个update如果更新了10000条数据，那么对应的表结构信息是否需要记录10000次?其实是对同一个表的操作，所以这里binlog只是记录了一个Table_map用于记录表结构相关信息,而后面的Update_rows记录了更新数据的行信息。注意此表中的table_id是会变化的。
- 然后使用/usr/local/mysql/bin目录下的mysqlbinlog工具解析binlog日志
[mysqladmin@hadoop001 bin]$ mysqlbinlog --start-position="3954" --stop-position="4158" /usr/local/mysql/arch/mysql-bin.000016
/*!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 3954
#190309 8:21:44 server id 1 end_log_pos 4025 CRC32 0xf962b4b1 Table_map: `hlwtest`.`emp` mapped to number 71
# at 4025
#190309 8:21:44 server id 1 end_log_pos 4127 CRC32 0x5013e9f3 Update_rows: table id 71 flags: STMT_END_F
BINLOG '
GAeDXBMBAAAARwAAALkPAAAAAEcAAAAAAAEAB2hsd3Rlc3QAA2VtcAAI9g8P9hL29vYPBAAKAAkA
BAAABwIHAgIA/rG0Yvk=
GAeDXB8BAAAAZgAAAB8QAAAAAEcAAAAAAAEAAgAI//8Al3EEU0lXQQhERVNJR05FUptZmaKQAACA
A+gAgBdwAKgAl3EEU0lXQQhERVNJR05FUptZmaKQAACAAfQAgBdwAKjz6RNQ
'/*!*/;
# at 4127
#190309 8:21:44 server id 1 end_log_pos 4158 CRC32 0xfc03c0c3 Xid = 138
COMMIT/*!*/;
DELIMITER ;
# End of log file
ROLLBACK /* added by mysqlbinlog */;
/*!50003 SET COMPLETION_TYPE=@OLD_COMPLETION_TYPE*/;
/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=0*/;- 加上参数（–base64-output=decode-rows -v）对输出结果解码
[mysqladmin@hadoop001 bin]$ mysqlbinlog --base64-output=decode-rows -v --start-position="3954" --stop-position="4158" /usr/local/mysql/arch/mysql-bin.000016
/*!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 3954
#190309 8:21:44 server id 1 end_log_pos 4025 CRC32 0xf962b4b1 Table_map: `hlwtest`.`emp` mapped to number 71
# at 4025
#190309 8:21:44 server id 1 end_log_pos 4127 CRC32 0x5013e9f3 Update_rows: table id 71 flags: STMT_END_F
### UPDATE `hlwtest`.`emp`
### WHERE
### @1=6001
### @2='SIWA'
### @3='DESIGNER'
### @4=7001
### @5='2019-03-08 00:00:00'
### @6=1000.00
### @7=6000.00
### @8=40
### SET
### @1=6001
### @2='SIWA'
### @3='DESIGNER'
### @4=7001
### @5='2019-03-08 00:00:00'
### @6=500.00
### @7=6000.00
### @8=40
# at 4127
#190309 8:21:44 server id 1 end_log_pos 4158 CRC32 0xfc03c0c3 Xid = 138
COMMIT/*!*/;
DELIMITER ;
# End of log file
ROLLBACK /* added by mysqlbinlog */;
/*!50003 SET COMPLETION_TYPE=@OLD_COMPLETION_TYPE*/;
/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=0*/;可以看到Mysql每次列的修改（update）都需要记录表中所有列的值。这样就存在一个问题，如果表中包含很多的大字段，表的单行长度就会非常长，这样每次update就会导致大量的 binlog空间生成。针对这个问题，在mysql 5.6中进行了改进，复制支持”row image control” ，只记录修改的列而不是行中所有的列，这对一些包含 BLOGs 字段的数据来说可以节省很大的处理能力，因此此项改进不仅节省了磁盘空间，同时也提升了性能。
当数据库的binlog format 是statement 模式时，查看下binlog日志
mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000017 | 355 | | | |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
mysql> show binlog events in 'mysql-bin.000017';
+------------------+-----+-------------+-----------+-------------+--------------------------------------------------------+
| Log_name | Pos | Event_type | Server_id | End_log_pos | Info |
+------------------+-----+-------------+-----------+-------------+--------------------------------------------------------+
| mysql-bin.000017 | 4 | Format_desc | 1 | 120 | Server ver: 5.6.23-log, Binlog ver: 4 |
| mysql-bin.000017 | 120 | Query | 1 | 205 | BEGIN |
| mysql-bin.000017 | 205 | Query | 1 | 324 | use `hlwtest`; update emp set sal=501 where empno=6001 |
| mysql-bin.000017 | 324 | Xid | 1 | 355 | COMMIT /* xid=24 */ |
+------------------+-----+-------------+-----------+-------------+--------------------------------------------------------+
4 rows in set (0.01 sec)
//使用/usr/local/mysql/bin目录下的mysqlbinlog工具解析binlog日志
[mysqladmin@hadoop001 ~]$ /usr/local/mysql/bin/mysqlbinlog /usr/local/mysql/arch/mysql-bin.000017
...
# at 205
#190309 9:00:29 server id 1 end_log_pos 324 CRC32 0x1c4a065d Query thread_id=3 exec_time=0 error_code=0
use `hlwtest`/*!*/;
SET TIMESTAMP=1552093229/*!*/;
update emp set sal=501 where empno=6001
/*!*/;
# at 324
#190309 9:00:29 server id 1 end_log_pos 355 CRC32 0xf7071a73 Xid = 24
COMMIT/*!*/;
...注意：
Maxwell是读取的MySQL主从架构的从库的binlog。在主从之间binlog不同的格式可能造成丢数据的情况，并且在从库中把参数read_only开启，只能在从库进行读操作，来避免主从数据不一致。
mysql> show variables like '%read_only%';
+------------------+-------+
| Variable_name | Value |
+------------------+-------+
| innodb_read_only | OFF |
| read_only | OFF |
| tx_read_only | OFF |
+------------------+-------+
3 rows in set (0.01 sec)目前这三个参数是处于关闭状态，因此我们需要开启他们。binlog的格式有三种，statement，mixed，row；其中mixed为MySQL5.1的过渡产品，现在不用这种格式，statement能够看到完整的sql语句，row不能看到完整的sql语句，但是在MySQL5.6中开启参数binlog_rows_query_log_events也能看到完整的SQL语句。
结论：
在binlog格式为statement时，容易出现跨库操作丢失数据的情况，在row格式下最安全，不会出现跨库丢失数据的情况。statement的优点为占用磁盘空间比较小。row的缺点是一行一行的记录SQL，占用空间比较大。
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