GTID_LIST_EVENT

Logged during binlog rotation or checkpoints, this event lists the GTIDs present in the binary log to help replicas determine their replication state.

Logged in every binlog to record the current replication state. Consists of the last GTID seen for each replication domain.

The Global Transaction ID, GTID for short, consists of three components:

• Replication domain ID;

• Master server ID;

• Sequence ID.

It's represented as three numbers separated with dashes (-); for example: 1-1222-1011 .

It's usually written after the Format Description Event. If binary log encryption is enabled, it is written after the Start Encryption Event.

In case of encrypted binlog files (encrypt_binlog is set to ON), this event is written just after the START_ENCRYPTION_EVENT.

Header

• Event type is 163 (0xa3).

Fields

• uint<4> Number of GTIDs.

• For (i=0; i < gtid_count; i++):

  • uint<4> Replication Domain ID.

  • uint<4> Server_ID.

  • uint<8> GTID sequence.

The minimum content size for one GTID is 4 + (4 + 4 + 8) * 1 = 20 bytes .

Example With 1 GTID, With CRC32

From the mysqlbinlog utility:

170824 9:52:04 server id 10124 end_log_pos 292 CRC32 0xb6d8f0a8 Gtid list [0-10124-3584]

a4 85 9e 59 a3 8c 27 00  00 2b 00 00 00 24 01 00  ...Y..'..+...$..
00 00 00 01 00 00 00 00  00 00 00 8c 27 00 00 00  ............'...
0e 00 00 00 00 00 00 a8  f0 d8 b6                 ..........

Header, 19 Bytes

• Event Time = a4 85 9e 59 ===> 2017-08-24 9:52:04.

• Event Type = a3 => 163.

• Server_id = 8c 27 00 00 => 00 00 27 8c => 10124.

• Event Size = 2b => 43 (header[19] + 1 GTID(20 bytes) + CRC32[4].

• Next Pos = 24 01 00 00 => 00 00 01 24 => 292.

• Flags = 00 => 0.

Content, Variable Size, is (4 + (4 + 4 + 8 ) * n_GTIDs) Bytes

The content example with one GTID is 20 bytes + 4 bytes CRC32:

• Number of GTIDs[4] = 01 00 00 00 => 1.

• GTID[0] replication_domain[4] = 00 00 00 00 => 0.

• GTID[0] Server_id[4] = 8c 27 00 00 => 00 00 27 8c => 10124.

• GTID[0] Sequence[8] = 00 0e 00 00 00 00 00 00 ===> 3584.

• crc32[4] = a8 f0 d8 b6 => b6 d8 f0 a8 => 0xb6d8f0a8.

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