#include <gcs_event_handlers.h>

Inheritance diagram for Plugin_gcs_events_handler:

Public Member Functions
	Plugin_gcs_events_handler (Applier_module_interface applier_module, Recovery_module recovery_module, Compatibility_module *compatibility_manager, ulong components_stop_timeout)
	Plugin_gcs_events_handler constructor. More...

	~Plugin_gcs_events_handler () override

void	on_message_received (const Gcs_message &message) const override
	This method is called whenever a message is to be delivered. More...

void	on_view_changed (const Gcs_view &new_view, const Exchanged_data &exchanged_data) const override
	This method is called when the view is ready to be installed. More...

Gcs_message_data *	get_exchangeable_data () const override
	This method is called when the Data Exchange is about to happen in order for the client to provide which data it wants to exchange with the group. More...

void	on_suspicions (const std::vector< Gcs_member_identifier > &members, const std::vector< Gcs_member_identifier > &unreachable) const override
	This member function is called when the set of suspicions has changed in the underlying communication infrastructure. More...

void	set_stop_wait_timeout (ulong timeout)
	Sets the component stop timeout. More...

void	disable_read_mode_for_compatible_members (bool force_check=false) const
	This function disable read-only mode when member version is compatible with group. More...

Public Member Functions inherited from Gcs_communication_event_listener
virtual	~Gcs_communication_event_listener ()=default

Public Member Functions inherited from Gcs_control_event_listener
virtual	~Gcs_control_event_listener ()=default

Private Member Functions
void	handle_transactional_message (const Gcs_message &message) const

void	handle_recovery_metadata (const Gcs_message &message) const

void	handle_transactional_with_guarantee_message (const Gcs_message &message) const

void	handle_transaction_prepared_message (const Gcs_message &message) const

void	handle_sync_before_execution_message (const Gcs_message &message) const

void	handle_certifier_message (const Gcs_message &message) const

void	handle_recovery_message (Plugin_gcs_message *message) const

void	handle_stats_message (const Gcs_message &message) const

void	handle_single_primary_message (Plugin_gcs_message *processed_message) const

void	handle_group_action_message (const Gcs_message &message) const

bool	pre_process_message (Plugin_gcs_message *plugin_message, const std::string &message_origin) const
	This method passes the message to message listeners. More...

int	update_group_info_manager (const Gcs_view &new_view, const Exchanged_data &exchanged_data, bool is_joining, bool is_leaving) const

void	handle_joining_members (const Gcs_view &new_view, bool is_joining, bool is_leaving) const

void	handle_leaving_members (const Gcs_view &new_view, bool is_joining, bool is_leaving) const

void	update_member_status (const std::vector< Gcs_member_identifier > &members, Group_member_info::Group_member_status status, Group_member_info::Group_member_status old_equal_to, Group_member_info::Group_member_status old_different_from) const
	This method updates the status of the members in the list according to the given parameters. More...

void	handle_leader_election_if_needed (enum_primary_election_mode election_mode, std::string &suggested_primary) const
	This method handles the election of a new primary node when the plugin runs in single primary mode. More...

int	process_local_exchanged_data (const Exchanged_data &exchanged_data, bool is_joining) const

bool	is_member_on_vector (const std::vector< Gcs_member_identifier > &members, const Gcs_member_identifier &member_id) const
	Verifies if a certain Vector of Member Ids contains a given member id. More...

int	check_group_compatibility (size_t number_of_members) const
	Checks the compatibility of the member with the group. More...

st_compatibility_types	check_version_compatibility_with_group () const
	When the member is joining, cycle through all members on group and see if it is compatible with them. More...

int	compare_member_transaction_sets () const
	Method that compares the group's aggregated GTID set against the joiner GTID set. More...

void	collect_members_executed_sets (View_change_packet *view_packet) const
	This method takes all the group executed sets and adds those belonging to non recovering member to the view change packet. More...

int	compare_member_option_compatibility () const
	Method that compares the member options with the value of the same option on all other members. More...

bool	is_group_running_a_configuration_change (std::string &group_action_running_initiator, std::string &group_action_running_description) const
	Check if a member is not entering a group where an action is running. More...

bool	is_group_running_a_primary_election () const
	Check if the group is running a primary election. More...

bool	was_member_expelled_from_group (const Gcs_view &view) const
	This method checks if member was expelled from the group due to network failures. More...

void	log_members_joining_message (const Gcs_view &new_view) const
	Logs member joining message to error logs from view. More...

void	log_messages_during_member_leave (const Gcs_view &new_view) const
	Logs member leaving message to error logs from view. More...

void	get_hosts_from_view (const std::vector< Gcs_member_identifier > &members, std::string &all_hosts, std::string &primary_host) const
	This function return all members present in vector of Gcs_member_identifier in HOST:PORT format separated by comma. More...

void	leave_group_on_recovery_metadata_error (std::string error_message) const
	Leave group on recovering metadata error. More...

Private Attributes
Applier_module_interface *	applier_module

Recovery_module *	recovery_module

std::set< Group_member_info , Group_member_info_pointer_comparator >	temporary_states

Compatibility_module *	compatibility_manager

st_compatibility_types *	joiner_compatibility_status
	The status of this member when it joins. More...

ulong	stop_wait_timeout

bool	set_number_of_members_on_view_changed_to_10

Notification_context	m_notification_ctx
	The notification context for the GCS delivery thread. More...

Constructor & Destructor Documentation

◆ Plugin_gcs_events_handler()

Plugin_gcs_events_handler::Plugin_gcs_events_handler	(	Applier_module_interface *	applier_module,
		Recovery_module *	recovery_module,
		Compatibility_module *	compatibility_manager,
		ulong	components_stop_timeout
	)

Plugin_gcs_events_handler constructor.

It receives, via the constructor, all the necessary dependencies to work.

◆ ~Plugin_gcs_events_handler()

Plugin_gcs_events_handler::~Plugin_gcs_events_handler ( )

override

Member Function Documentation

◆ check_group_compatibility()

int Plugin_gcs_events_handler::check_group_compatibility ( size_t number_of_members ) const

private

Checks the compatibility of the member with the group.

Here we check: 1) If the number of members was exceeded 2) If member version is compatible with the group 3) If the gtid_assignment_block_size is equal to the group 4) If the hash algorithm used is equal to the group 5) If the member has more known transactions than the group 6) If the member has the same configuration flags that the group has.

It checks: 1) If the number of members was exceeded 2) If member version is compatible with the group 3) If the gtid_assignment_block_size is equal to the group 4) If the hash algorithm used is equal to the group 5) If the member has more known transactions than the group

Parameters

number_of_members the number of members in the new view

Return values

0	compatible
>0	not compatible with the group

◆ check_version_compatibility_with_group()

Compatibility_type Plugin_gcs_events_handler::check_version_compatibility_with_group ( ) const

private

When the member is joining, cycle through all members on group and see if it is compatible with them.

Returns: the compatibility with the group

Return values

INCOMPATIBLE	//Versions not compatible
COMPATIBLE	//Versions compatible
READ_COMPATIBLE	//Member can read but not write

◆ collect_members_executed_sets()

void Plugin_gcs_events_handler::collect_members_executed_sets ( View_change_packet * view_packet ) const

private

This method takes all the group executed sets and adds those belonging to non recovering member to the view change packet.

Parameters

[in] view_packet the view change packet

◆ compare_member_option_compatibility()

int Plugin_gcs_events_handler::compare_member_option_compatibility ( ) const

private

Method that compares the member options with the value of the same option on all other members.

It compares: 1) GTID assignment block size 2) Write set hash algorithm

Return values

0	Joiner has the same value as all other members
!=0	Otherwise

◆ compare_member_transaction_sets()

int Plugin_gcs_events_handler::compare_member_transaction_sets ( ) const

private

Method that compares the group's aggregated GTID set against the joiner GTID set.

These sets contain executed and received GTIDs present in the relay log files belonging to each member plugin applier channel.

Returns: if the joiner has more GTIDs then the group.

Return values

0	Joiner has less GTIDs than the group
>0	Joiner has more GTIDS than the group
<0	Error when processing GTID information

◆ disable_read_mode_for_compatible_members()

void Plugin_gcs_events_handler::disable_read_mode_for_compatible_members ( bool force_check = false ) const

This function disable read-only mode when member version is compatible with group.

Parameters

[in] force_check Compatibility is mandatory re-checked

◆ get_exchangeable_data()

Gcs_message_data * Plugin_gcs_events_handler::get_exchangeable_data ( ) const

overridevirtual

This method is called when the Data Exchange is about to happen in order for the client to provide which data it wants to exchange with the group.

Returns: a reference to the exchangeable data. This is a pointer that must be deallocated by the caller, so please provide always a copy of the data to exchange.

Implements Gcs_control_event_listener.

◆ get_hosts_from_view()

void Plugin_gcs_events_handler::get_hosts_from_view	(	const std::vector< Gcs_member_identifier > &	members,
		std::string &	all_hosts,
		std::string &	primary_host
	)		const

private

This function return all members present in vector of Gcs_member_identifier in HOST:PORT format separated by comma.

Function also return PRIMARY member if any in HOST:PORT format.

Parameters

[in]	members	joining or leaving members for this view
[out]	all_hosts	host and port of all members from view
[out]	primary_host	primary member hosts and port of all members from view

Check in_primary_mode has been added for safety. Since primary role is in single-primary mode.

◆ handle_certifier_message()

void Plugin_gcs_events_handler::handle_certifier_message ( const Gcs_message & message ) const

private

◆ handle_group_action_message()

void Plugin_gcs_events_handler::handle_group_action_message ( const Gcs_message & message ) const

private

◆ handle_joining_members()

void Plugin_gcs_events_handler::handle_joining_members	(	const Gcs_view &	new_view,
		bool	is_joining,
		bool	is_leaving
	)		const

private

On the joining list there can be 3 types of members: 1) ONLINE/RECOVERING members coming from old views where this member was not present; 2) new joining members that still have their status as OFFLINE; 3) old members that were expelled and did auto-rejoin, that have their status as ERROR.

As so, for members with state OFFLINE and ERROR, their state is changed to RECOVERING after member compatibility with group is checked.

Is an election running while I'm joining?

Set the read mode if not set during start (auto-start)

On the joining member log an error when group contains more members than auto_increment_increment variable.

On the joining list there can be 3 types of members: 1) ONLINE/RECOVERING members coming from old views where this member was not present; 2) new joining members that still have their status as OFFLINE; 3) old members that were expelled and did auto-rejoin, that have their status as ERROR.

As so, for members with state OFFLINE and ERROR, their state is changed to RECOVERING after member compatibility with group is checked.

If not a joining member, all members should record on their own binlogs a marking event that identifies the frontier between the data the joining member was to receive and the data it should queue. The joining member can then wait for this event to know it was all the needed data.

This packet will also pass in the certification process at this exact frontier giving us the opportunity to gather the necessary certification information to certify the transactions that will come after this view change. If selected as a donor, this info will also be sent to the joiner.

Associated to this process, we collect and intersect the executed GTID sets of all ONLINE members so we can cut the certification info to gather and transmit to the minimum.

◆ handle_leader_election_if_needed()

void Plugin_gcs_events_handler::handle_leader_election_if_needed	(	enum_primary_election_mode	election_mode,
		std::string &	suggested_primary
	)		const

private

This method handles the election of a new primary node when the plugin runs in single primary mode.

Parameters

election_mode	election type
suggested_primary	what should be the next primary to elect

Note: This function unsets the super read only mode on primary node and sets it on secondary nodes

◆ handle_leaving_members()

void Plugin_gcs_events_handler::handle_leaving_members	(	const Gcs_view &	new_view,
		bool	is_joining,
		bool	is_leaving
	)		const

private

◆ handle_recovery_message()

void Plugin_gcs_events_handler::handle_recovery_message ( Plugin_gcs_message * message ) const

private

Re-check compatibility, members may leave during recovery. Disable the read mode in the server if the member is:

joining
doesn't have a higher possible incompatible version
We are not on Primary mode.

◆ handle_recovery_metadata()

void Plugin_gcs_events_handler::handle_recovery_metadata ( const Gcs_message & message ) const

private

Check if the View_ID in the received recovery metadata matches with the locally stored View_ID on the joiner. This locally stored View_ID is on which joining member joined the group.

View_ID matches it's JOINER: a. It means the joiner has received the metadata and it can use it to recover and come ONLINE. b. Also local copy of View_ID stored in Recovery_metadata_joiner_information can be removed. c. It also creates a copy of recovery metadata which is processed later by recovery thread. GCS thread which holds current copy of recovery metadata may delete it before recovery process it, so another copy needs to be created. d. Awake Recovery module waiting for Metadata to be received.
View_ID does not match it's SENDER: e. The recovery metadata broadcast was successful now local copy of recovery metadata is deleted.
If there is error, cleanup and member leaves the group.

◆ handle_single_primary_message()

void Plugin_gcs_events_handler::handle_single_primary_message ( Plugin_gcs_message * processed_message ) const

private

◆ handle_stats_message()

void Plugin_gcs_events_handler::handle_stats_message ( const Gcs_message & message ) const

private

◆ handle_sync_before_execution_message()

void Plugin_gcs_events_handler::handle_sync_before_execution_message ( const Gcs_message & message ) const

private

◆ handle_transaction_prepared_message()

void Plugin_gcs_events_handler::handle_transaction_prepared_message ( const Gcs_message & message ) const

private

◆ handle_transactional_message()

void Plugin_gcs_events_handler::handle_transactional_message ( const Gcs_message & message ) const

private

◆ handle_transactional_with_guarantee_message()

void Plugin_gcs_events_handler::handle_transactional_with_guarantee_message ( const Gcs_message & message ) const

private

◆ is_group_running_a_configuration_change()

bool Plugin_gcs_events_handler::is_group_running_a_configuration_change	(	std::string &	group_action_running_initiator,
		std::string &	group_action_running_description
	)		const

private

Check if a member is not entering a group where an action is running.

If action is running provide details of action.

Parameters

[out]	group_action_running_initiator	Group action configuration initiator details
[out]	group_action_running_description	Group action configuration description

Return values

false	no group action is running
true	a group action is running

◆ is_group_running_a_primary_election()

bool Plugin_gcs_events_handler::is_group_running_a_primary_election ( ) const

private

Check if the group is running a primary election.

Return values

false	no primary election is running
true	a primary election is running

◆ is_member_on_vector()

bool Plugin_gcs_events_handler::is_member_on_vector	(	const std::vector< Gcs_member_identifier > &	members,
		const Gcs_member_identifier &	member_id
	)		const

private

Verifies if a certain Vector of Member Ids contains a given member id.

Parameters

members	the vector with members to verify
member_id	the member to check if it contained.

Returns: true if member_id occurs in members.

◆ leave_group_on_recovery_metadata_error()

void Plugin_gcs_events_handler::leave_group_on_recovery_metadata_error ( std::string error_message ) const

private

Leave group on recovering metadata error.

Parameters

[in] error_message Log error message on member leave.

◆ log_members_joining_message()

void Plugin_gcs_events_handler::log_members_joining_message ( const Gcs_view & new_view ) const

private

Logs member joining message to error logs from view.

Parameters

[in] new_view the view delivered by the GCS

◆ log_messages_during_member_leave()

void Plugin_gcs_events_handler::log_messages_during_member_leave ( const Gcs_view & new_view ) const

private

Logs member leaving message to error logs from view.

Parameters

[in] new_view the view delivered by the GCS

◆ on_message_received()

void Plugin_gcs_events_handler::on_message_received ( const Gcs_message & message ) const

overridevirtual

This method is called whenever a message is to be delivered.

Parameters

[in] message The received message. This is currently a reference to avoid the existence of dangling pointers.

From this point messages are sent to message listeners and may be skipped Messages above are directly processed and/or for performance we do not want to add that extra weight.

Implements Gcs_communication_event_listener.

◆ on_suspicions()

void Plugin_gcs_events_handler::on_suspicions	(	const std::vector< Gcs_member_identifier > &	members,
		const std::vector< Gcs_member_identifier > &	unreachable
	)		const

overridevirtual

This member function is called when the set of suspicions has changed in the underlying communication infrastructure.

Parameters

[in]	members	Contains the list of all members that are in the current view.
[in]	unreachable	Contains the list of members that are unreachable in the current view, i.e., a subset of `members`.

Implements Gcs_control_event_listener.

◆ on_view_changed()

void Plugin_gcs_events_handler::on_view_changed	(	const Gcs_view &	new_view,
		const Exchanged_data &	exchanged_data
	)		const

overridevirtual

This method is called when the view is ready to be installed.

The contents of Exchanged_data will be released by MySQL GCS after this handler finishes. Therefore the application MUST copy the contents of exchanged_data if it needs it at a later stage.

Parameters

[in]	new_view	a reference to the new view.
[in]	exchanged_data	the data handed out by other members.

Implements Gcs_control_event_listener.

◆ pre_process_message()

bool Plugin_gcs_events_handler::pre_process_message	(	Plugin_gcs_message *	plugin_message,
		const std::string &	message_origin
	)		const

private

This method passes the message to message listeners.

Parameters

plugin_message	A pointer to the processed plugin gcs message
message_origin	A id of the message originating member

Returns: true if the message should be skipped, false otherwise

◆ process_local_exchanged_data()

int Plugin_gcs_events_handler::process_local_exchanged_data	(	const Exchanged_data &	exchanged_data,
		bool	is_joining
	)		const

private

◆ set_stop_wait_timeout()

void Plugin_gcs_events_handler::set_stop_wait_timeout ( ulong timeout )

inline

Sets the component stop timeout.

Parameters

[in] timeout the timeout

◆ update_group_info_manager()

int Plugin_gcs_events_handler::update_group_info_manager	(	const Gcs_view &	new_view,
		const Exchanged_data &	exchanged_data,
		bool	is_joining,
		bool	is_leaving
	)		const

private

◆ update_member_status()

void Plugin_gcs_events_handler::update_member_status	(	const std::vector< Gcs_member_identifier > &	members,
		Group_member_info::Group_member_status	status,
		Group_member_info::Group_member_status	old_equal_to,
		Group_member_info::Group_member_status	old_different_from
	)		const

private

This method updates the status of the members in the list according to the given parameters.

Parameters

members	the vector with members to change the status to
status	the status to change to.
old_equal_to	change if the old status is equal to
old_different_from	change if the old status if different from

Note: When not using the old_equal_to and old_different_from parameters, you can pass the Group_member_info::MEMBER_END value.

◆ was_member_expelled_from_group()

bool Plugin_gcs_events_handler::was_member_expelled_from_group ( const Gcs_view & view ) const

private

This method checks if member was expelled from the group due to network failures.

Parameters

[in] view the view delivered by the GCS

Return values

true	the member was expelled
false	otherwise

Member Data Documentation

◆ applier_module

Applier_module_interface* Plugin_gcs_events_handler::applier_module

private

◆ compatibility_manager

Compatibility_module* Plugin_gcs_events_handler::compatibility_manager

private

◆ joiner_compatibility_status

st_compatibility_types* Plugin_gcs_events_handler::joiner_compatibility_status

private

The status of this member when it joins.

◆ m_notification_ctx

Notification_context Plugin_gcs_events_handler::m_notification_ctx

mutableprivate

The notification context for the GCS delivery thread.

◆ recovery_module

Recovery_module* Plugin_gcs_events_handler::recovery_module

private

◆ set_number_of_members_on_view_changed_to_10

bool Plugin_gcs_events_handler::set_number_of_members_on_view_changed_to_10

private

◆ stop_wait_timeout

ulong Plugin_gcs_events_handler::stop_wait_timeout

private

◆ temporary_states

std::set<Group_member_info *, Group_member_info_pointer_comparator>* Plugin_gcs_events_handler::temporary_states

private

The documentation for this class was generated from the following files:

plugin/group_replication/include/gcs_event_handlers.h
plugin/group_replication/src/gcs_event_handlers.cc

Public Member Functions

Private Member Functions

Private Attributes

Constructor & Destructor Documentation

◆ Plugin_gcs_events_handler()

◆ ~Plugin_gcs_events_handler()

Member Function Documentation

◆ check_group_compatibility()

◆ check_version_compatibility_with_group()

◆ collect_members_executed_sets()

◆ compare_member_option_compatibility()

◆ compare_member_transaction_sets()

◆ disable_read_mode_for_compatible_members()

◆ get_exchangeable_data()

◆ get_hosts_from_view()

◆ handle_certifier_message()

◆ handle_group_action_message()

◆ handle_joining_members()

◆ handle_leader_election_if_needed()

◆ handle_leaving_members()

◆ handle_recovery_message()

◆ handle_recovery_metadata()

◆ handle_single_primary_message()

◆ handle_stats_message()

◆ handle_sync_before_execution_message()

◆ handle_transaction_prepared_message()

◆ handle_transactional_message()

◆ handle_transactional_with_guarantee_message()

◆ is_group_running_a_configuration_change()

◆ is_group_running_a_primary_election()

◆ is_member_on_vector()

◆ leave_group_on_recovery_metadata_error()

◆ log_members_joining_message()

◆ log_messages_during_member_leave()

◆ on_message_received()

◆ on_suspicions()

◆ on_view_changed()

◆ pre_process_message()

◆ process_local_exchanged_data()

◆ set_stop_wait_timeout()

◆ update_group_info_manager()

◆ update_member_status()

◆ was_member_expelled_from_group()

Member Data Documentation

◆ applier_module

◆ compatibility_manager

◆ joiner_compatibility_status

◆ m_notification_ctx

◆ recovery_module

◆ set_number_of_members_on_view_changed_to_10

◆ stop_wait_timeout

◆ temporary_states