Replication event to ensure to replica that source is alive. More...

#include <control_events.h>

Inheritance diagram for binary_log::Heartbeat_event:

Public Member Functions
	Heartbeat_event (const char buf, const Format_description_event fde)
	Sent by a source to a replica to let the replica know that the source is still alive. More...

const char *	get_log_ident ()

unsigned int	get_ident_len ()

Public Member Functions inherited from binary_log::Binary_log_event
virtual	~Binary_log_event ()=0

	Binary_log_event (const Binary_log_event &)=default

	Binary_log_event (Binary_log_event &&)=default

Binary_log_event &	operator= (const Binary_log_event &)=default

Binary_log_event &	operator= (Binary_log_event &&)=default

enum Log_event_type	get_event_type () const
	Helper method. More...

const Log_event_header *	header () const
	Return a const pointer to the header of the log event. More...

Log_event_header *	header ()
	Return a non-const pointer to the header of the log event. More...

const Log_event_footer *	footer () const
	Return a const pointer to the footer of the log event. More...

Log_event_footer *	footer ()
	Return a non-const pointer to the footer of the log event. More...

Event_reader &	reader ()
	Returns a reference to the event Event_reader object. More...

Protected Attributes
const char *	log_ident

unsigned int	ident_len

Additional Inherited Members
Public Types inherited from binary_log::Binary_log_event
enum	enum_post_header_length { QUERY_HEADER_MINIMAL_LEN = (4 + 4 + 1 + 2) , QUERY_HEADER_LEN = (QUERY_HEADER_MINIMAL_LEN + 2) , STOP_HEADER_LEN = 0 , START_V3_HEADER_LEN = (2 + ST_SERVER_VER_LEN + 4) , ROTATE_HEADER_LEN = 8 , INTVAR_HEADER_LEN = 0 , APPEND_BLOCK_HEADER_LEN = 4 , DELETE_FILE_HEADER_LEN = 4 , RAND_HEADER_LEN = 0 , USER_VAR_HEADER_LEN = 0 , FORMAT_DESCRIPTION_HEADER_LEN = (START_V3_HEADER_LEN + 1 + LOG_EVENT_TYPES) , XID_HEADER_LEN = 0 , BEGIN_LOAD_QUERY_HEADER_LEN = APPEND_BLOCK_HEADER_LEN , ROWS_HEADER_LEN_V1 = 8 , TABLE_MAP_HEADER_LEN = 8 , EXECUTE_LOAD_QUERY_EXTRA_HEADER_LEN = (4 + 4 + 4 + 1) , EXECUTE_LOAD_QUERY_HEADER_LEN , INCIDENT_HEADER_LEN = 2 , HEARTBEAT_HEADER_LEN = 0 , IGNORABLE_HEADER_LEN = 0 , ROWS_HEADER_LEN_V2 = 10 , TRANSACTION_CONTEXT_HEADER_LEN = 18 , VIEW_CHANGE_HEADER_LEN = 52 , XA_PREPARE_HEADER_LEN = 0 , TRANSACTION_PAYLOAD_HEADER_LEN = 0 }
	The lengths for the fixed data part of each event. More...

Static Public Attributes inherited from binary_log::Binary_log_event
static const int	LOG_EVENT_TYPES = (ENUM_END_EVENT - 1)

Protected Member Functions inherited from binary_log::Binary_log_event
	Binary_log_event (Log_event_type type_code)
	This constructor is used to initialize the type_code of header object m_header. More...

	Binary_log_event (const char *buf, const Format_description_event fde)
	This constructor will create a new object of Log_event_header and initialize the variable m_header, which in turn will be used to initialize Log_event's member common_header. More...

Detailed Description

Replication event to ensure to replica that source is alive.

The event is originated by source's dump thread and sent straight to replica without being logged. Slave itself does not store it in relay log but rather uses a data for immediate checks and throws away the event.

Two members of the class log_ident and Binary_log_event::log_pos comprise

See also: the rpl_event_coordinates instance. The coordinates that a heartbeat instance carries correspond to the last event source has sent from its binlog.

Binary Format

The Body has one component:

Body for Heartbeat_event
Name	Format	Description
log_ident	variable length string without trailing zero, extending to the end of the event	Name of the current binlog being written to.

Constructor & Destructor Documentation

◆ Heartbeat_event()

binary_log::Heartbeat_event::Heartbeat_event	(	const char *	buf,
		const Format_description_event *	fde
	)

Sent by a source to a replica to let the replica know that the source is still alive.

Events of this type do not appear in the binary or relay logs. They are generated on a source server by the thread that dumps events and sent straight to the replica without ever being written to the binary log.

Parameters

buf	Contains the serialized event.
fde	An FDE event (see Rotate_event constructor for more info).

Member Function Documentation

◆ get_ident_len()

unsigned int binary_log::Heartbeat_event::get_ident_len ( )

inline

◆ get_log_ident()

const char * binary_log::Heartbeat_event::get_log_ident ( )

inline

Member Data Documentation

◆ ident_len

unsigned int binary_log::Heartbeat_event::ident_len

protected

◆ log_ident

const char* binary_log::Heartbeat_event::log_ident