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.

    2. binlog事件的变化

    1.   / New MySQL/Sun events are to be added right above this comment /
    2.   MYSQL_EVENTS_END,
    3.  
    4.   MARIA_EVENTS_BEGIN= 160,
    5.   / New Maria event numbers start from here /
    6.   ANNOTATE_ROWS_EVENT= 160,
    7.  
    8.   / Add new MariaDB events here - right above this comment!  /
    9.  
    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.

    • 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.

    2. 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.  
    25.   / Add new MariaDB events here - right above this comment!  /
    26.  
    27.   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.

    2. 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 + “‘“