COM_BINLOG_DUMP - Source

Revision: 123666
User: Massimiliano Pinto
Date: 2023-02-27 07:54

This is a command the slave sends to the master after [[com_register_slave|COM_REGISTER_SLAVE]].

The master server sends the [[/1-binlog-events|binlog events]] from the requested file and position, or if GTID registration is in use, from the GTID value set in the earlier registration phase.

The payload is:

<<style style="padding: 16px;background-color: #f7f7f7;border-radius: 3px;">>
* [[protocol-data-types/#fixed-length-bytes| uint<1>]] command  (COM_BINLOG_DUMP = 0x12)
* [[protocol-data-types/#fixed-length-bytes| uint<4>]] The requested binlog position
* [[protocol-data-types/#fixed-length-bytes| uint<2>]] Flags
* [[protocol-data-types/#fixed-length-bytes| uint<4>]] Slave server_id
* [[protocol-data-types/#fixed-length-bytes| string<EOF>]] The requested binlog file name
<</style>>

**Note**
* Flags, usually set to 0.\\
It can be set to BINLOG_SEND_ANNOTATE_ROWS_EVENT (0x02)\\
if the slave server wants to receive the MariaDB 10 [[annotate_rows_event|ANNOTATE_ROWS]] events.\\
It can also be set to BINLOG_DUMP_NON_BLOCK (1):\\
in the case the slave is receiving an EOF packet after last event sent by the master.\\
* Requested binlog position can be 4 when registering to master server for the very first time\\
or when requesting events from a particular binlog file from the beginning of it.
* The requested binlog file can empty when registering for the very first time if master log file is unknown\\
or with GTID registration (not required).\\
* After sending events to the replica the server kills connection.

When replication resumes or it is restarted (STOP SLAVE; START SLAVE) the slave server always\\
sends the latest binlog file name and position even if GTID registration is in place.

==== Example of COM_BINLOG_DUMP

{{{
  1b 00 00 00 12 34 06 00    00 02 00 75 27 00 00 6d    .....4.....u'..m
  79 73 71 6c 2d 62 69 6e    2e 30 30 30 30 33 34       ysql-bin.000034 
}}}

After 4 bytes network protocol header we can see:

* command [1] = **12**
* requested binlog position [4] = 34 06 00  00 => 00 00 06 34 = **1588**
* flags [2] = 02 00 => **2** = BINLOG_SEND_ANNOTATE_ROWS_EVENT
* binlog file[n] = **mysql-bin.000034**

Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.

COM_BINLOG_DUMP - Source

Products

Services

Pricing

Resources

About Us

Download MariaDB