本文主要是介绍一下canal支持mariadb协议上的变化.

协议变化

mariadb5.5

mariadb5.5主要是基于mysql5.5的原型，类型定义基本没啥变化，大体上都保持兼容

主要的变化：

  1. QueryLogEvent增加了status变量.

  2. Q_HRNOW 用于记录毫秒的精度，枚举值下标为128

协议解析的时候，需要处理Q_HRNOW，需要跳过3字节的数据.

ps. mysql5.6后，新增了Q_MICROSECONDS来支持mariaDb中Q_HRNOW的毫秒精度的功能.

  1. binlog事件的变化
1. / New MySQL/Sun events are to be added right above this comment /
2. MYSQL_EVENTS_END,

4. MARIA_EVENTS_BEGIN= 160,
5. / New Maria event numbers start from here /
6. ANNOTATE_ROWS_EVENT= 160,

8. / Add new MariaDB events here - right above this comment!  /

10. ENUM_END_EVENT / end marker /

新增了mariadb的binlog区间为160开始，ANNOTATE_ROWS_EVENT类型为mysql5.6中的RowsQueryLogEvent，用于记录RBR模式下insert/update/delete中执行的sql.

mariadb10

mariadb10主要是基于mysql5.6的原型，类型定义基本没啥变化，大体上都保持兼容(沿用了mysql5.6中TIMESTAMP2等新的时间类型和新的log_event类型)

主要的变化：

  1. QueryLogEvent增加了status变量.

  2. Q_HRNOW 用于记录毫秒的精度，枚举值下标为128

协议解析的时候，需要处理Q_HRNOW，需要跳过3字节的数据.

ps. mysql5.6后，新增了Q_MICROSECONDS来支持mariaDb中Q_HRNOW的毫秒精度的功能.

  1. binlog事件的变化
1. MARIA_EVENTS_BEGIN= 160,
2. / New Maria event numbers start from here /
3. ANNOTATE_ROWS_EVENT= 160,
4. /
5. Binlog checkpoint event. Used for XA crash recovery on the master, not used
6. in replication.
7. A binlog checkpoint event specifies a binlog file such that XA crash
8. recovery can start from that file - and it is guaranteed to find all XIDs
9. that are prepared in storage engines but not yet committed.
10. /
11. BINLOG_CHECKPOINT_EVENT= 161,
12. /
13. Gtid event. For global transaction ID, used to start a new event group,
14. instead of the old BEGIN query event, and also to mark stand-alone
15. events.
16. /
17. GTID_EVENT= 162,
18. /
19. Gtid list event. Logged at the start of every binlog, to record the
20. current replication state. This consists of the last GTID seen for
21. each replication domain.
22. /
23. GTID_LIST_EVENT= 163,

25. / Add new MariaDB events here - right above this comment!  /

27. ENUM_END_EVENT / end marker /

新增了mariadb自己的gtid处理

使用注意

  1. AnnotateRowsEvent使用

  2. mariadb需要在my.cnf中设置binlog_annotate_row_events = true，开启记录annotate事件

  3. canal在发送COM_BINLOG_DUMP指令中需要设置binlog_flags |= BINLOG_SEND_ANNOTATE_ROWS_EVENT，不然mariadb默认不会发送AnnotateRowsEvent，而是以空的QueryLogEvent来代替.

  4. 新增的binlog类型使用

  5. canal需要设置当前session变量

java 1. SET @mariadb_slave_capability=’” + LogEvent.MARIA_SLAVE_CAPABILITY_MINE + “‘“