GTID_EVENT

The GTID_EVENT marks the start of a new transaction event group, associating it with a Global Transaction ID (GTID) and providing commit flags.

For global transaction ID, used to start a new transaction event group, instead of the old BEGIN query event, and also to mark stand-alone (DDL).

GTID_EVENT event type is 162 (0xa2).

Event Header

• Type[1] = 0xa2.

• Flags[2] = 08 00 => LOG_EVENT_SUPPRESS_USE_F.

Fields

• uint<8> GTID sequence.

• uint<4> Replication Domain ID.

• uint<1> Flags.

If flag & FL_GROUP_COMMIT_ID:

• uint<8> commit_id.

Else if flag & (FL_PREPARED_XA or FL_COMPLETED_XA):

• uint<4> format_id.

• uint<1> gtid_length.

• uint<1> bqual_length.

• byte xid, where n is sum of gtrid and bqual lengths.

Else:

• uint<6> 0.

Flags

Flag	Value	Details
FL_STANDALONE	1	Set when there is no terminating COMMIT event.
FL_GROUP_COMMIT_ID	2	Set when event group is part of a group commit on the master. Groups with same commit_id are part of the same group commit.
FL_TRANSACTIONAL	4	Set for an event group that can be safely rolled back (no MyISAM, for instance).
FL_ALLOW_PARALLEL	8	Reflects the (negation of the) value of @@SESSION.skip_parallel_replication at the time of commit.
FL_WAITED	16	Set if a row lock wait (or other wait) is detected during the execution of the transaction.
FL_DDL	32	Set for event group containing DDL.
FL_PREPARED_XA	64	Set for XA transaction.
FL_COMPLETED_XA	128	XA transaction completed (committed or rolled back).

Transaction Example From mysqlbinlog Utility

BEGIN
#171205 18:22:52 server id 10124  end_log_pos 652 CRC32 0x23c8d337 	GTID 0-10124-9884 trans
TBALE_MAP
#171205 18:22:52 server id 10124  end_log_pos 752 CRC32 0x52601513 	Table_map: `test`.`t4` mapped to number 92
WRITE
#171205 18:22:52 server id 10124  end_log_pos 790 CRC32 0x8869c123 	Write_rows: table id 92 flags: STMT_END_F
COMMIT
#171205 18:22:52 server id 10124  end_log_pos 821 CRC32 0x15517636 	Xid = 42004

Standalone Event DDL (FLUSH TABLES) From mysqlbinlog Utility

#171205 17:44:27 server id 10124  end_log_pos 535 CRC32 0x309a668e 	GTID 0-10124-9883 ddl
#171205 17:44:27 server id 10124  end_log_pos 610 CRC32 0xda151470 	Query	thread_id=819	...

Example GTID_EVENT with DDL and CRC32

eb cc 26 5a a2 8c 27 00  00 2a 00 00 00 17 02 00  ...&Z..'..*.....
00 08 00 9b 26 00 00 00  00 00 00 00 00 00 00 29  ...&..........).
00 00 00 00 00 00 8e 66  9a 30                    ......f.0.

Content

• GTID seq[8] = 9b 26 00 00 00 00 00 00 => 9883.

• domain id[4] = 00 00 00 00 00 => 0.

• flags[1] = 29 => 41 (FL_DDL =32 + FL_ALLOW_PARALLEL=8 + FL_STANDALONE=1).

• commit_id[6] = 00 00 00 00 00 00 = 0.

• CRC32[4] = 8e 66 9a 30.

Example GTID_EVENT With a Transaction and CRC32

ec d5 26 5a a2 8c 27 00  00 2a 00 00 00 8c 02 00 ..&Z..'..*......
00 08 00 9c 26 00 00 00  00 00 00 00 00 00 00 0c ....&...........
00 00 00 00 00 00 37 d3  c8 23                   ......7..#

Content

• GTID seq[8] = 9c 26 00 00 00 00 00 00 => 9884.

• domain id[4] = 00 00 00 00 00 => 0.

• flags[1] = 0c => 12 (FL_ALLOW_PARALLEL=8 + FL_TRANSACTIONAL=4).

• commit_id[6] = 00 00 00 00 00 00 = 0.

• CRC32[4] = 37 d3 c8 23.

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