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.
  • 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,
  3. MARIA_EVENTS_BEGIN= 160,
  4. /* New Maria event numbers start from here */
  5. ANNOTATE_ROWS_EVENT= 160,
  6. /* Add new MariaDB events here - right above this comment!  */
  7. 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.
  • 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,
  24. /* Add new MariaDB events here - right above this comment!  */
  25. ENUM_END_EVENT /* end marker */

新增了mariadb自己的gtid处理

使用注意

  1. AnnotateRowsEvent使用
  • mariadb需要在my.cnf中设置binlog_annotate_row_events = true，开启记录annotate事件
  • 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.
  1. 新增的binlog类型使用
  • canal需要设置当前session变量
  1. SET @mariadb_slave_capability='" + LogEvent.MARIA_SLAVE_CAPABILITY_MINE + "'"