Certifier Class Reference

#include <certifier.h>

Inheritance diagram for Certifier:

Public Types
typedef std::unordered_map< std::string, Gtid_set_ref *, std::hash< std::string >, std::equal_to< std::string >, Malloc_allocator< std::pair< const std::string, Gtid_set_ref * > > >	Certification_info

Public Member Functions
	Certifier ()
	~Certifier () override
int	initialize (ulonglong gtid_assignment_block_size)
	Initialize certifier. More...
int	terminate ()
	Terminate certifier. More...
void	handle_view_change () override
	Handle view changes on certifier. More...
int	handle_certifier_data (const uchar *data, ulong len, const Gcs_member_identifier &gcs_member_id) override
	Queues the packet coming from the reader for future processing. More...
rpl_gno	certify (Gtid_set *snapshot_version, std::list< const char * > *write_set, bool generate_group_id, const char *member_uuid, Gtid_log_event *gle, bool local_transaction)
	This member function SHALL certify the set of items against transactions that have already passed the certification test. More...
int	get_group_stable_transactions_set_string (char **buffer, size_t *length) override
	Returns the transactions in stable set in text format, that is, the set of transactions already applied on all group members. More...
void	get_certification_info (std::map< std::string, std::string > *cert_info) override
	Retrieves the current certification info. More...
int	set_certification_info (std::map< std::string, std::string > *cert_info) override
	Sets the certification info according to the given value. More...
ulonglong	get_positive_certified () override
	Get the number of postively certified transactions by the certifier. More...
ulonglong	get_negative_certified () override
	Get method to retrieve the number of negatively certified transactions. More...
ulonglong	get_certification_info_size () override
	Get method to retrieve the certification db size. More...
void	get_last_conflict_free_transaction (std::string *value) override
	Get method to retrieve the last conflict free transaction. More...
Gtid	generate_view_change_group_gtid ()
	Generate group GTID for a view change log event. More...
int	add_group_gtid_to_group_gtid_executed (rpl_gno gno)
	Public method to add the given gno value to the group_gtid_executed set which is used to support skip gtid functionality. More...
int	add_specified_gtid_to_group_gtid_executed (Gtid_log_event *gle)
	Public method to add the given GTID value in the group_gtid_executed set which is used to support skip gtid functionality. More...
int	stable_set_handle () override
	Computes intersection between all sets received, so that we have the already applied transactions on all servers. More...
bool	set_group_stable_transactions_set (Gtid_set *executed_gtid_set) override
	This member function shall add transactions to the stable set. More...
void	enable_conflict_detection () override
	Enables conflict detection. More...
void	disable_conflict_detection () override
	Disables conflict detection. More...
bool	is_conflict_detection_enable () override
	Check if conflict detection is enable. More...
Public Member Functions inherited from Certifier_interface
	~Certifier_interface () override=default
Public Member Functions inherited from Certifier_stats
virtual	~Certifier_stats ()=default

Static Public Attributes
static const std::string	CERTIFICATION_INFO_ERROR_NAME
	Key used to store errors in the certification info on View_change_log_event. More...

Private Member Functions
int	initialize_server_gtid_set (bool get_server_gtid_retrieved=false)
	Method to initialize the group_gtid_executed gtid set with the server gtid executed set and applier retrieved gtid set values. More...
void	compute_group_available_gtid_intervals ()
	This function computes the available GTID intervals from group UUID and stores them on group_available_gtid_intervals. More...
Gtid_set::Interval	reserve_gtid_block (longlong block_size)
	This function reserves a block of GTIDs from the group_available_gtid_intervals list. More...
void	update_parallel_applier_indexes (bool update_parallel_applier_last_committed_global, bool increment_parallel_applier_sequence_number)
	This function updates parallel applier indexes. More...
void	add_to_group_gtid_executed_internal (rpl_sidno sidno, rpl_gno gno)
	Internal method to add the given gtid gno in the group_gtid_executed set. More...
rpl_gno	get_next_available_gtid (const char *member_uuid, rpl_sidno sidno)
	This method is used to get the next valid GNO for the given sidno, for the transaction that is being executed. More...
rpl_gno	get_group_next_available_gtid (const char *member_uuid)
	This method is used to get the next valid GNO for the transaction that is being executed. More...
rpl_gno	get_next_available_gtid_candidate (rpl_sidno sidno, rpl_gno start, rpl_gno end) const
	Generate the candidate GNO for the current transaction. More...
bool	is_initialized ()
void	clear_certification_info ()
void	clear_members ()
	Method to clear the members. More...
bool	add_item (const char *item, Gtid_set_ref *snapshot_version, int64 *item_previous_sequence_number)
	Adds an item from transaction writeset to the certification DB. More...
Gtid_set *	get_certified_write_set_snapshot_version (const char *item)
	Find the snapshot_version corresponding to an item. More...
void	garbage_collect ()
	Removes the intersection of the received transactions stable sets from certification database. More...
void	clear_incoming ()
	Clear incoming queue. More...
void	update_certified_transaction_count (bool result, bool local_transaction)

Private Attributes
std::atomic< bool >	initialized {false}
	Is certifier initialized. More...
rpl_sidno	group_gtid_sid_map_group_sidno
	Variable to store the sidno used for transactions which will be logged with the group_uuid. More...
rpl_sidno	views_sidno_group_representation
	The sidno used for view log events as seen by the group sid map. More...
rpl_sidno	views_sidno_server_representation
	The sidno used for view log events as seen by the server sid map. More...
Gtid	last_conflict_free_transaction
	Last conflict free transaction identification. More...
Certification_info	certification_info
	Certification database. More...
Sid_map *	certification_info_sid_map
ulonglong	positive_cert
ulonglong	negative_cert
int64	parallel_applier_last_committed_global
int64	parallel_applier_last_sequence_number
int64	parallel_applier_sequence_number
bool	certifier_garbage_collection_block
bool	same_member_message_discarded
mysql_mutex_t	LOCK_certification_info
Checkable_rwlock *	stable_gtid_set_lock
	Stable set and garbage collector variables. More...
Sid_map *	stable_sid_map
Gtid_set *	stable_gtid_set
Synchronized_queue< Data_packet * > *	incoming
std::vector< std::string >	members
bool	certifying_already_applied_transactions
Sid_map *	group_gtid_sid_map
Gtid_set *	group_gtid_executed
Gtid_set *	group_gtid_extracted
	A Gtid_set which contains the gtid extracted from the certification info map of the donor. More...
uint64	gtid_assignment_block_size
	The group GTID assignment block size. More...
std::list< Gtid_set::Interval >	group_available_gtid_intervals
	List of free GTID intervals in group. More...
std::map< std::string, Gtid_set::Interval >	member_gtids
	Extends the above to allow GTIDs to be assigned in blocks per member. More...
ulonglong	gtids_assigned_in_blocks_counter
bool	conflict_detection_enable
	Conflict detection is performed when: 1) group is on multi-master mode; 2) group is on single-primary mode and primary is applying relay logs with transactions from a previous primary. More...
mysql_mutex_t	LOCK_members
Certifier_broadcast_thread *	broadcast_thread
	Broadcast thread. More...

Static Private Attributes
static const std::string	GTID_EXTRACTED_NAME = "gtid_extracted"
	Key used to store group_gtid_executed on certification info on View_change_log_event. More...

Member Typedef Documentation

Certification_info

typedef std::unordered_map< std::string, Gtid_set_ref *, std::hash<std::string>, std::equal_to<std::string>, Malloc_allocator<std::pair<const std::string, Gtid_set_ref *> > > Certifier::Certification_info

Constructor & Destructor Documentation

Certifier()

Certifier::Certifier

(

)

~Certifier()

Certifier::~Certifier ( )

override

Member Function Documentation

add_group_gtid_to_group_gtid_executed()

int Certifier::add_group_gtid_to_group_gtid_executed

(

rpl_gno

gno

)

Public method to add the given gno value to the group_gtid_executed set which is used to support skip gtid functionality.

Parameters

[in]

gno

The gno of the transaction which will be added to the group_gtid executed GTID set. The sidno used for this transaction will be the group_sidno. The gno here belongs specifically to the group UUID.

Return values

1	error during addition.
0	success.

add_item()

bool Certifier::add_item ( const char *  item, Gtid_set_ref *  snapshot_version, int64 *  item_previous_sequence_number  )

private

Adds an item from transaction writeset to the certification DB.

Parameters

[in]	item	item in the writeset to be added to the Certification DB.
[in]	snapshot_version	Snapshot version of the incoming transaction which modified the above mentioned item.
[out]	item_previous_sequence_number	The previous parallel applier sequence number for this item.

Return values

False

successfully added to the map. True otherwise.

add_specified_gtid_to_group_gtid_executed()

int Certifier::add_specified_gtid_to_group_gtid_executed

(

Gtid_log_event *

gle

)

Public method to add the given GTID value in the group_gtid_executed set which is used to support skip gtid functionality.

Parameters

[in]

gle

The gtid value that needs to the added in the group_gtid_executed GTID set.

Return values

1	error during addition.
0	success.

add_to_group_gtid_executed_internal()

void Certifier::add_to_group_gtid_executed_internal ( rpl_sidno  sidno, rpl_gno  gno  )

private

Internal method to add the given gtid gno in the group_gtid_executed set.

This will be used in the skip gtid implementation.

Note

this will update the last know local transaction GTID.

Parameters

[in]	sidno	rpl_sidno part of the executing gtid of the ongoing transaction.
[in]	gno	rpl_gno part of the executing gtid of the ongoing transaction.

certify()

rpl_gno Certifier::certify	(	Gtid_set *	snapshot_version,
		std::list< const char * > *	write_set,
		bool	generate_group_id,
		const char *	member_uuid,
		Gtid_log_event *	gle,
		bool	local_transaction
	)

This member function SHALL certify the set of items against transactions that have already passed the certification test.

Parameters

snapshot_version	The incoming transaction snapshot version.
write_set	The incoming transaction write set.
generate_group_id	Flag that indicates if transaction group id must be generated.
member_uuid	The UUID of the member from which this transaction originates.
gle	The incoming transaction global identifier event.
local_transaction	True if this transaction did originate from this member, false otherwise.

Return values

>0	transaction identifier (positively certified). If generate_group_id is false and certification positive a 1 is returned;
0	negatively certified;
-1	error.

clear_certification_info()

void Certifier::clear_certification_info ( )

private

clear_incoming()

void Certifier::clear_incoming ( )

private

Clear incoming queue.

clear_members()

void Certifier::clear_members ( )

private

Method to clear the members.

compute_group_available_gtid_intervals()

void Certifier::compute_group_available_gtid_intervals ( )

private

This function computes the available GTID intervals from group UUID and stores them on group_available_gtid_intervals.

disable_conflict_detection()

void Certifier::disable_conflict_detection ( )

overridevirtual

Disables conflict detection.

Implements Certifier_interface.

enable_conflict_detection()

void Certifier::enable_conflict_detection ( )

overridevirtual

Enables conflict detection.

Implements Certifier_interface.

garbage_collect()

void Certifier::garbage_collect ( )

private

Removes the intersection of the received transactions stable sets from certification database.

generate_view_change_group_gtid()

Gtid Certifier::generate_view_change_group_gtid

(

)

Generate group GTID for a view change log event.

Return values

>0	view change GTID
otherwise	Error on GTID generation

get_certification_info()

void Certifier::get_certification_info ( std::map< std::string, std::string > *  cert_info )

overridevirtual

Retrieves the current certification info.

Note

if concurrent access is introduce to these variables, locking is needed in this method

Parameters

[out]

cert_info

a pointer to retrieve the certification info

Implements Certifier_interface.

get_certification_info_size()

ulonglong Certifier::get_certification_info_size ( )

overridevirtual

Get method to retrieve the certification db size.

Implements Certifier_interface.

get_certified_write_set_snapshot_version()

Gtid_set * Certifier::get_certified_write_set_snapshot_version ( const char *  item )

private

Find the snapshot_version corresponding to an item.

Return if it exists, other wise return NULL;

Parameters

[in]

item

item for the snapshot version.

Return values

Gtid_set

pointer if exists in the map. Otherwise 0;

get_group_next_available_gtid()

rpl_gno Certifier::get_group_next_available_gtid ( const char *  member_uuid )

private

This method is used to get the next valid GNO for the transaction that is being executed.

It checks the already used up GNOs and based on that chooses the next possible value. This method will consult group_available_gtid_intervals to assign GTIDs in blocks according to gtid_assignment_block_size.

Parameters

member_uuid

The UUID of the member from which this transaction originates. It will be NULL on View_change_log_event.

Return values

>0	The GNO to be used.
-1	Error: GNOs exhausted for group UUID.

get_group_stable_transactions_set_string()

int Certifier::get_group_stable_transactions_set_string ( char **  buffer, size_t *  length  )

overridevirtual

Returns the transactions in stable set in text format, that is, the set of transactions already applied on all group members.

Parameters

[out]	buffer	Pointer to pointer to string. The method will set it to point to the newly allocated buffer, or NULL on out of memory. Caller must free the allocated memory.
[out]	length	Length of the generated string.

Returns

the operation status

Return values

0	OK
!=0	Out of memory error

Implements Certifier_stats.

get_last_conflict_free_transaction()

void Certifier::get_last_conflict_free_transaction ( std::string *  value )

overridevirtual

Get method to retrieve the last conflict free transaction.

Parameters

[out]

value

The last conflict free transaction

Implements Certifier_stats.

get_negative_certified()

ulonglong Certifier::get_negative_certified ( )

overridevirtual

Get method to retrieve the number of negatively certified transactions.

Implements Certifier_stats.

get_next_available_gtid()

rpl_gno Certifier::get_next_available_gtid ( const char *  member_uuid, rpl_sidno  sidno  )

private

This method is used to get the next valid GNO for the given sidno, for the transaction that is being executed.

It checks the already used up GNOs and based on that chooses the next possible value. This method will consult group_available_gtid_intervals to assign GTIDs in blocks according to gtid_assignment_block_size when sidno is the group sidno.

Parameters

member_uuid	The UUID of the member from which this transaction originates. It will be NULL on View_change_log_event.
sidno	The sidno that will be used on GTID

Return values

>0	The GNO to be used.
-1	Error: GNOs exhausted for group UUID.

get_next_available_gtid_candidate()

rpl_gno Certifier::get_next_available_gtid_candidate ( rpl_sidno  sidno, rpl_gno  start, rpl_gno  end  ) const

private

Generate the candidate GNO for the current transaction.

The candidate will be on the interval [start, end] or a error be returned. This method will consult group_gtid_executed to avoid generate the same value twice.

Parameters

sidno	The sidno that will be used to retrieve GNO
start	The first possible value for the GNO
end	The last possible value for the GNO

Return values

>0	The GNO to be used.
-1	Error: GNOs exhausted for group UUID.
-2	Error: generated GNO is bigger than end.

get_positive_certified()

ulonglong Certifier::get_positive_certified ( )

overridevirtual

Get the number of postively certified transactions by the certifier.

Implements Certifier_stats.

handle_certifier_data()

int Certifier::handle_certifier_data ( const uchar *  data, ulong  len, const Gcs_member_identifier &  gcs_member_id  )

overridevirtual

Queues the packet coming from the reader for future processing.

Parameters

[in]	data	the packet data
[in]	len	the packet length
[in]	gcs_member_id	the member_id which sent the message

Returns

the operation status

Return values

0	OK
!=0	Error on queue

Implements Certifier_interface.

handle_view_change()

void Certifier::handle_view_change ( )

overridevirtual

Handle view changes on certifier.

Implements Certifier_interface.

initialize()

int Certifier::initialize

(

ulonglong

gtid_assignment_block_size

)

Initialize certifier.

Parameters

gtid_assignment_block_size

the group gtid assignment block size

Returns

the operation status

Return values

0	OK
!=0	Error

initialize_server_gtid_set()

int Certifier::initialize_server_gtid_set ( bool  get_server_gtid_retrieved = false )

private

Method to initialize the group_gtid_executed gtid set with the server gtid executed set and applier retrieved gtid set values.

Parameters

get_server_gtid_retrieved

add applier retrieved gtid set to group_gtid_executed gtid set

Return values

1	error during initialization
0	success

is_conflict_detection_enable()

bool Certifier::is_conflict_detection_enable ( )

overridevirtual

Check if conflict detection is enable.

Return values

True	conflict detection is enable
False	otherwise

Implements Certifier_interface.

is_initialized()

bool Certifier::is_initialized ( )

inlineprivate

reserve_gtid_block()

Gtid_set::Interval Certifier::reserve_gtid_block ( longlong  block_size )

private

This function reserves a block of GTIDs from the group_available_gtid_intervals list.

Return values

Gtid_set::Interval

which is the interval os GTIDs attributed

set_certification_info()

int Certifier::set_certification_info ( std::map< std::string, std::string > *  cert_info )

overridevirtual

Sets the certification info according to the given value.

Note

if concurrent access is introduce to these variables, locking is needed in this method

Parameters

[in]

cert_info

certification info retrieved from recovery procedure

Return values

>	0 Error during setting certification info.
=	0 Everything went fine.

Implements Certifier_interface.

set_group_stable_transactions_set()

bool Certifier::set_group_stable_transactions_set ( Gtid_set *  executed_gtid_set )

overridevirtual

This member function shall add transactions to the stable set.

Parameters

executed_gtid_set

The GTID set of the transactions to be added to the stable set.

Note

when set, the stable set will cause the garbage collection process to be invoked

Return values

False	if adds successfully,
True	otherwise.

Implements Certifier_interface.

stable_set_handle()

int Certifier::stable_set_handle ( )

overridevirtual

Computes intersection between all sets received, so that we have the already applied transactions on all servers.

Returns

the operation status

Return values

0	OK
!=0	Error

Implements Certifier_interface.

terminate()

int Certifier::terminate

(

)

Terminate certifier.

Returns

the operation status

Return values

0	OK
!=0	Error

update_certified_transaction_count()

void Certifier::update_certified_transaction_count ( bool  result, bool  local_transaction  )

private

update_parallel_applier_indexes()

void Certifier::update_parallel_applier_indexes ( bool  update_parallel_applier_last_committed_global, bool  increment_parallel_applier_sequence_number  )

private

This function updates parallel applier indexes.

It must be called for each remote transaction.

Parameters

[in]	update_parallel_applier_last_committed_global	If true parallel_applier_last_committed_global is updated to the current sequence number (before update sequence number).
[in]	increment_parallel_applier_sequence_number	If false (during certification garbage collection) parallel_applier_last_committed_global is set to parallel_applier_last_sequence_number and parallel_applier_last_sequence_number is not updated

Note: parallel_applier_last_committed_global should be updated on the following situations: 1) Transaction without write set is certified, since it represents the lowest last_committed for all future transactions; 2) After certification info garbage collection, since we do not know what write sets were purged, which may cause transactions last committed to be incorrectly computed.

Member Data Documentation

broadcast_thread

Certifier_broadcast_thread* Certifier::broadcast_thread

private

Broadcast thread.

certification_info

Certification_info Certifier::certification_info

private

Certification database.

CERTIFICATION_INFO_ERROR_NAME

const std::string Certifier::CERTIFICATION_INFO_ERROR_NAME

static

Initial value:

=
    "certification_info_error"

Key used to store errors in the certification info on View_change_log_event.

certification_info_sid_map

Sid_map* Certifier::certification_info_sid_map

private

certifier_garbage_collection_block

bool Certifier::certifier_garbage_collection_block

private

certifying_already_applied_transactions

bool Certifier::certifying_already_applied_transactions

private

conflict_detection_enable

bool Certifier::conflict_detection_enable

private

Conflict detection is performed when: 1) group is on multi-master mode; 2) group is on single-primary mode and primary is applying relay logs with transactions from a previous primary.

group_available_gtid_intervals

std::list<Gtid_set::Interval> Certifier::group_available_gtid_intervals

private

List of free GTID intervals in group.

group_gtid_executed

Gtid_set* Certifier::group_gtid_executed

private

group_gtid_extracted

Gtid_set* Certifier::group_gtid_extracted

private

A Gtid_set which contains the gtid extracted from the certification info map of the donor.

It is the set of transactions that is executed at the time of View_change_log_event at donor.

group_gtid_sid_map

Sid_map* Certifier::group_gtid_sid_map

private

group_gtid_sid_map_group_sidno

rpl_sidno Certifier::group_gtid_sid_map_group_sidno

private

Variable to store the sidno used for transactions which will be logged with the group_uuid.

gtid_assignment_block_size

uint64 Certifier::gtid_assignment_block_size

private

The group GTID assignment block size.

GTID_EXTRACTED_NAME

const std::string Certifier::GTID_EXTRACTED_NAME = "gtid_extracted"

staticprivate

Key used to store group_gtid_executed on certification info on View_change_log_event.

gtids_assigned_in_blocks_counter

ulonglong Certifier::gtids_assigned_in_blocks_counter

private

incoming

Synchronized_queue<Data_packet *>* Certifier::incoming

private

initialized

std::atomic<bool> Certifier::initialized {false}

private

Is certifier initialized.

last_conflict_free_transaction

Gtid Certifier::last_conflict_free_transaction

private

Last conflict free transaction identification.

LOCK_certification_info

mysql_mutex_t Certifier::LOCK_certification_info

private

LOCK_members

mysql_mutex_t Certifier::LOCK_members

private

member_gtids

std::map<std::string, Gtid_set::Interval> Certifier::member_gtids

private

Extends the above to allow GTIDs to be assigned in blocks per member.

members

std::vector<std::string> Certifier::members

private

negative_cert

ulonglong Certifier::negative_cert

private

parallel_applier_last_committed_global

int64 Certifier::parallel_applier_last_committed_global

private

parallel_applier_last_sequence_number

int64 Certifier::parallel_applier_last_sequence_number

private

parallel_applier_sequence_number

int64 Certifier::parallel_applier_sequence_number

private

positive_cert

ulonglong Certifier::positive_cert

private

same_member_message_discarded

bool Certifier::same_member_message_discarded

private

stable_gtid_set

Gtid_set* Certifier::stable_gtid_set

private

stable_gtid_set_lock

Checkable_rwlock* Certifier::stable_gtid_set_lock

private

Stable set and garbage collector variables.

stable_sid_map

Sid_map* Certifier::stable_sid_map

private

views_sidno_group_representation

rpl_sidno Certifier::views_sidno_group_representation

private

The sidno used for view log events as seen by the group sid map.

views_sidno_server_representation

rpl_sidno Certifier::views_sidno_server_representation

private

The sidno used for view log events as seen by the server sid map.

---

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

• plugin/group_replication/include/certifier.h
• plugin/group_replication/src/certifier.cc