#include <gcs_xcom_group_management.h>

Inheritance diagram for Gcs_xcom_group_management:

Public Member Functions
	Gcs_xcom_group_management (Gcs_xcom_proxy xcom_proxy, const Gcs_group_identifier &group_identifier, Gcs_xcom_view_change_control_interface view_control)

	~Gcs_xcom_group_management () override

enum_gcs_error	modify_configuration (const Gcs_interface_parameters &reconfigured_group) override
	Method that allows sending of a new group configuration. More...

enum_gcs_error	get_write_concurrency (uint32_t &event_horizon) const override
	Retrieves the group's "write concurrency" value. More...

enum_gcs_error	set_write_concurrency (uint32_t event_horizon) override
	Reconfigures the group's "write concurrency" value. More...

enum_gcs_error	set_single_leader (Gcs_member_identifier const &leader) override
	Reconfigures the group's "consensus leaders.". More...

enum_gcs_error	set_everyone_leader () override
	Reconfigures the group's "consensus leaders.". More...

enum_gcs_error	get_leaders (std::vector< Gcs_member_identifier > &preferred_leaders, std::vector< Gcs_member_identifier > &actual_leaders) override
	Inspect the group's "consensus leader" configuration. More...

uint32_t	get_minimum_write_concurrency () const override
	Retrieves the minimum supported "write concurrency" value. More...

uint32_t	get_maximum_write_concurrency () const override
	Retrieves the maximum supported "write concurrency" value. More...

void	set_xcom_nodes (const Gcs_xcom_nodes &xcom_nodes)
	Save information on the latest nodes seen by this node so that it can safely reconfigure the group if it loses the majority. More...

void	get_xcom_nodes (Gcs_xcom_nodes &result_xcom_nodes, const std::vector< std::string > &filter)

void	get_xcom_nodes (Gcs_xcom_nodes &result_xcom_nodes, const std::vector< Gcs_member_identifier > &filter)

void	get_xcom_nodes (Gcs_xcom_nodes &result_xcom_nodes, const std::vector< Gcs_member_identifier * > &filter)

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

Private Member Functions
	Gcs_xcom_group_management (Gcs_xcom_group_management const &)

Gcs_xcom_group_management &	operator= (Gcs_xcom_group_management const &)

Private Attributes
Gcs_xcom_proxy *	m_xcom_proxy

Gcs_group_identifier *	m_gid

Gcs_xcom_nodes	m_xcom_nodes

unsigned int	m_gid_hash

My_xp_mutex_impl	m_nodes_mutex

Gcs_xcom_view_change_control_interface *	m_view_control

Constructor & Destructor Documentation

◆ Gcs_xcom_group_management() [1/2]

Gcs_xcom_group_management::Gcs_xcom_group_management	(	Gcs_xcom_proxy *	xcom_proxy,
		const Gcs_group_identifier &	group_identifier,
		Gcs_xcom_view_change_control_interface *	view_control
	)

explicit

◆ ~Gcs_xcom_group_management()

Gcs_xcom_group_management::~Gcs_xcom_group_management ( )

override

◆ Gcs_xcom_group_management() [2/2]

Gcs_xcom_group_management::Gcs_xcom_group_management ( Gcs_xcom_group_management const & )

private

Member Function Documentation

◆ get_leaders()

enum_gcs_error Gcs_xcom_group_management::get_leaders	(	std::vector< Gcs_member_identifier > &	preferred_leaders,
		std::vector< Gcs_member_identifier > &	actual_leaders
	)

overridevirtual

Inspect the group's "consensus leader" configuration.

Parameters

[out]	preferred_leaders	The members specified as preferred leaders.
[out]	actual_leaders	The members actually carrying out the leader role at this moment.

Return values

GCS_OK	if successful, `preferred_leaders` and `actual_leaders` contain the result
GCS_NOK	if unsuccessful

Implements Gcs_group_management_interface.

◆ get_maximum_write_concurrency()

uint32_t Gcs_xcom_group_management::get_maximum_write_concurrency ( ) const

overridevirtual

Retrieves the maximum supported "write concurrency" value.

Implements Gcs_group_management_interface.

◆ get_minimum_write_concurrency()

uint32_t Gcs_xcom_group_management::get_minimum_write_concurrency ( ) const

overridevirtual

Retrieves the minimum supported "write concurrency" value.

Implements Gcs_group_management_interface.

◆ get_write_concurrency()

enum_gcs_error Gcs_xcom_group_management::get_write_concurrency ( uint32_t & write_concurrency ) const

overridevirtual

Retrieves the group's "write concurrency" value.

Parameters

[out] write_concurrency A reference to where the group's "write concurrency" value will be written to

Return values

GCS_OK	if successful and write_concurrency has been written to
GCS_NOK	if GCS was unable to request the current "write concurrency" value from the underlying implementation

Implements Gcs_group_management_interface.

◆ get_xcom_nodes() [1/3]

void Gcs_xcom_group_management::get_xcom_nodes	(	Gcs_xcom_nodes &	result_xcom_nodes,
		const std::vector< Gcs_member_identifier * > &	filter
	)

◆ get_xcom_nodes() [2/3]

void Gcs_xcom_group_management::get_xcom_nodes	(	Gcs_xcom_nodes &	result_xcom_nodes,
		const std::vector< Gcs_member_identifier > &	filter
	)

◆ get_xcom_nodes() [3/3]

void Gcs_xcom_group_management::get_xcom_nodes	(	Gcs_xcom_nodes &	result_xcom_nodes,
		const std::vector< std::string > &	filter
	)

◆ modify_configuration()

enum_gcs_error Gcs_xcom_group_management::modify_configuration ( const Gcs_interface_parameters & reconfigured_group )

overridevirtual

Method that allows sending of a new group configuration.

This is to be used when the group is blocked due to a loss of majority and only on one node from the new group.

Implementations in each binding might have there specificities but some rules must be followed:

This should be a non-blocking call;
Typically, it shall cause a View Change, since we are forcing a new configuration.

Parameters

[in] reconfigured_group a list containing the new nodes

Implements Gcs_group_management_interface.

◆ operator=()

Gcs_xcom_group_management & Gcs_xcom_group_management::operator= ( Gcs_xcom_group_management const & )

private

◆ set_everyone_leader()

enum_gcs_error Gcs_xcom_group_management::set_everyone_leader ( )

overridevirtual

Reconfigures the group's "consensus leaders.".

Instructs the underlying GCS to use every member as a consensus leader.

Return values

GCS_OK	if successful
GCS_NOK	if unsuccessful

Implements Gcs_group_management_interface.

◆ set_single_leader()

enum_gcs_error Gcs_xcom_group_management::set_single_leader ( Gcs_member_identifier const & leader )

overridevirtual

Reconfigures the group's "consensus leaders.".

Instructs the underlying GCS to use leader as the single preferred consensus leader.

Parameters

leader The member you desire to act as a consensus leader.

Return values

GCS_OK	if successful
GCS_NOK	if unsuccessful

Implements Gcs_group_management_interface.

◆ set_write_concurrency()

enum_gcs_error Gcs_xcom_group_management::set_write_concurrency ( uint32_t write_concurrency )

overridevirtual

Reconfigures the group's "write concurrency" value.

The caller should ensure that the supplied value is between minimum_write_concurrency and maximum_write_concurrency.

The method is non-blocking, meaning that it shall only send the request to an underlying GCS. The final result can be polled via get_write_concurrency.

Parameters

write_concurrency The desired "write concurrency" value.

Return values

GCS_OK	if successful
GCS_NOK	if unsuccessful

Implements Gcs_group_management_interface.

◆ set_xcom_nodes()

void Gcs_xcom_group_management::set_xcom_nodes ( const Gcs_xcom_nodes & xcom_nodes )

Save information on the latest nodes seen by this node so that it can safely reconfigure the group if it loses the majority.

This information is required to extract the set of possible alive nodes and their UUIDs. If the UUIDs in the reconfiguration request do not match those stored in XCOM, it will not allow the reconfiguration to proceed.

Note also that the set of nodes is updated by the MySQL GCS thread whenever a new configuration is delivered and that a user thread is responsible for calling the reconfiguration process. If a user is trying to reconfigure the system, this usually and unfortunately means that it has lost the majority and nothing will be updated by the MySQL GCS thread. However, just for the sake of completeness, we will use a mutex here to control access to this data structure.

Finally, it is worth noting that we cannot use get_site_def() here because information on nodes could be concurrently updated by the XCOM thread and we cannot add a mutex to it.

Member Data Documentation

◆ m_gid

Gcs_group_identifier* Gcs_xcom_group_management::m_gid

private

◆ m_gid_hash

unsigned int Gcs_xcom_group_management::m_gid_hash

private

◆ m_nodes_mutex

My_xp_mutex_impl Gcs_xcom_group_management::m_nodes_mutex

private

◆ m_view_control

Gcs_xcom_view_change_control_interface* Gcs_xcom_group_management::m_view_control

private

◆ m_xcom_nodes

Gcs_xcom_nodes Gcs_xcom_group_management::m_xcom_nodes

private

◆ m_xcom_proxy

Gcs_xcom_proxy* Gcs_xcom_group_management::m_xcom_proxy

private

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

plugin/group_replication/libmysqlgcs/src/bindings/xcom/gcs_xcom_group_management.h
plugin/group_replication/libmysqlgcs/src/bindings/xcom/gcs_xcom_group_management.cc

Public Member Functions

Private Member Functions

Private Attributes

Constructor & Destructor Documentation

◆ Gcs_xcom_group_management() [1/2]

◆ ~Gcs_xcom_group_management()

◆ Gcs_xcom_group_management() [2/2]

Member Function Documentation

◆ get_leaders()

◆ get_maximum_write_concurrency()

◆ get_minimum_write_concurrency()

◆ get_write_concurrency()

◆ get_xcom_nodes() [1/3]

◆ get_xcom_nodes() [2/3]

◆ get_xcom_nodes() [3/3]

◆ modify_configuration()

◆ operator=()

◆ set_everyone_leader()

◆ set_single_leader()

◆ set_write_concurrency()

◆ set_xcom_nodes()

Member Data Documentation

◆ m_gid

◆ m_gid_hash

◆ m_nodes_mutex

◆ m_view_control

◆ m_xcom_nodes

◆ m_xcom_proxy