Certification_handler Class Reference

#include <certification_handler.h>

Inheritance diagram for Certification_handler:

Classes
struct	View_change_stored_info
	View change information information stored for delay. More...

Public Member Functions
	Certification_handler ()
	~Certification_handler () override
int	handle_event (Pipeline_event *ev, Continuation *cont) override
	Handling of an event as defined in the handler implementation. More...
int	handle_action (Pipeline_action *action) override
	Handling of an action as defined in the handler implementation. More...
int	initialize () override
	Initialization as defined in the handler implementation. More...
int	terminate () override
	Terminate the execution as defined in the handler implementation. More...
bool	is_unique () override
	This method identifies the handler as being unique. More...
int	get_role () override
	This method returns the handler role. More...
Certifier_interface *	get_certifier ()
int	set_certification_info (std::map< std::string, std::string > *cert_info)
Public Member Functions inherited from Event_handler
	Event_handler ()
virtual	~Event_handler ()=default
void	plug_next_handler (Event_handler *next_handler)
	Plug an handler to be the next in line for execution. More...
void	append (Event_handler *last_handler)
	Append an handler to be the last in line for execution. More...
int	terminate_pipeline ()
	Shutdown and delete all handlers in the pipeline. More...

Private Member Functions
int	set_transaction_context (Pipeline_event *pevent)
	Set transaction context for next event handler. More...
int	get_transaction_context (Pipeline_event *pevent, Transaction_context_log_event **tcle)
	Get transaction context set on previous event handler. More...
void	reset_transaction_context ()
	Reset transaction context. More...
int	handle_transaction_context (Pipeline_event *pevent, Continuation *cont)
	This method handles transaction context events by storing them so they can be used on next handler. More...
int	handle_transaction_id (Pipeline_event *pevent, Continuation *cont)
	This methods handles transaction identifier events, it does two tasks: More...
int	extract_certification_info (Pipeline_event *pevent, Continuation *cont)
int	inject_transactional_events (Pipeline_event *pevent, Gtid gtid, binlog::BgcTicket::ValueType bgc_ticket, Continuation *cont)
	Create a transactional block for the received log event GTID BEGIN EVENT COMMIT. More...
int	log_view_change_event_in_order (Pipeline_event *view_pevent, Continuation *cont)
	Try to log a view change event waiting for local certified transactions to finish. More...
binlog::BgcTicket::ValueType	generate_view_change_bgc_ticket ()
	Generate a commit order ticket for the View_change transaction. More...

Private Attributes
Certifier *	cert_module
THD *	applier_module_thd
rpl_sidno	group_sidno
Data_packet *	transaction_context_packet
Pipeline_event *	transaction_context_pevent
std::list< std::unique_ptr< View_change_stored_info > >	pending_view_change_events_waiting_for_consistent_transactions
	All the VC events pending application due to consistent transactions. More...

Additional Inherited Members
Static Public Member Functions inherited from Event_handler
static void	append_handler (Event_handler **pipeline, Event_handler *event_handler)
	Append an handler to a given pipeline. More...
static void	get_handler_by_role (Event_handler *pipeline, int role, Event_handler **event_handler)
	Returns an handler that plays the given role. More...
Protected Member Functions inherited from Event_handler
int	next (Pipeline_event *event, Continuation *continuation)
	Pass the event to the next handler in line. More...
int	next (Pipeline_action *action)
	Pass the action to the next handler in line. More...

Constructor & Destructor Documentation

Certification_handler()

Certification_handler::Certification_handler

(

)

~Certification_handler()

Certification_handler::~Certification_handler ( )

override

Member Function Documentation

extract_certification_info()

int Certification_handler::extract_certification_info ( Pipeline_event *  pevent, Continuation *  cont  )

private

generate_view_change_bgc_ticket()

binlog::BgcTicket::ValueType Certification_handler::generate_view_change_bgc_ticket ( )

private

Generate a commit order ticket for the View_change transaction.

More precisely it will: 1) increment the current ticket so that the all transactions ordered before view will have a ticket smaller than the one assigned to the view. 2) generate the ticket for the view. 3) increment again the current ticket so that all transactions ordered after the view will have a ticket greater that the one assigned to the view.

Returns

the ticket generated for the view

get_certifier()

Certifier_interface * Certification_handler::get_certifier

(

)

get_role()

int Certification_handler::get_role ( )

overridevirtual

This method returns the handler role.

Handlers can have different roles according to the tasks they represent. Is based on this role that certain components can extract and interact with pipeline handlers. This means that if a role is given to a singleton handler, no one else can have that role.

Returns

the handler role

Implements Event_handler.

get_transaction_context()

int Certification_handler::get_transaction_context ( Pipeline_event *  pevent, Transaction_context_log_event **  tcle  )

private

Get transaction context set on previous event handler.

Parameters

[in]	pevent	Pipeline event that wraps Gtid_log_event.
[out]	tcle	Transaction_context_log_event.

Returns

Operation status

Return values

0	OK
!=0	Error

handle_action()

int Certification_handler::handle_action ( Pipeline_action *  action )

overridevirtual

Handling of an action as defined in the handler implementation.

As the handler can be included in a pipeline, somewhere in the method, the handler.next(action) method shall be invoked to allow the passing of the action to the next handler.

Note

Actions should not be treated asynchronously and as so, Continuations are not used here. Errors are returned directly or passed by in the action if it includes support for such

Parameters

[in]

action

the pipeline event to be handled

Implements Event_handler.

handle_event()

int Certification_handler::handle_event ( Pipeline_event *  event, Continuation *  continuation  )

overridevirtual

Handling of an event as defined in the handler implementation.

As the handler can be included in a pipeline, somewhere in the method, the handler.next(event,continuation) method shall be invoked to allow the passing of the event to the next handler.

Also, if an error occurs, the continuation object shall be used to propagate such error. This class can also be used to know/report when the transaction to whom the event belongs was discarded.

Parameters

[in]	event	the pipeline event to be handled
[in,out]	continuation	termination notification object.

Implements Event_handler.

handle_transaction_context()

int Certification_handler::handle_transaction_context ( Pipeline_event *  pevent, Continuation *  cont  )

private

This method handles transaction context events by storing them so they can be used on next handler.

Parameters

[in]	pevent	the event to be injected
[in]	cont	the object used to wait

Returns

the operation status

Return values

0	OK
!=0	Error

handle_transaction_id()

int Certification_handler::handle_transaction_id ( Pipeline_event *  pevent, Continuation *  cont  )

private

This methods handles transaction identifier events, it does two tasks:

1. Using transaction context previously processed and stored, validate that this transaction does not conflict with any other;
2. If the transaction does not conflict and it is allowed to commit, it does inform the server of that decision and does update the transaction identifier if needed.

Parameters

[in]	pevent	the event to be injected
[in]	cont	the object used to wait

Returns

the operation status

Return values

0	OK
!=0	Error

initialize()

int Certification_handler::initialize ( )

overridevirtual

Initialization as defined in the handler implementation.

Note

It's up to the developer to decide its own initialization strategy, but the suggested approach is to initialize basic structures here and then depend on Action packets to configure and start existing handler routines.

Implements Event_handler.

inject_transactional_events()

int Certification_handler::inject_transactional_events ( Pipeline_event *  pevent, Gtid  gtid, binlog::BgcTicket::ValueType  bgc_ticket, Continuation *  cont  )

private

Create a transactional block for the received log event GTID BEGIN EVENT COMMIT.

Parameters

[in]	pevent	the event to be injected
[in]	gtid	The transaction GTID If {-1, -1}, one will be generated.
[in]	bgc_ticket	The commit ticket order for this transaction on the binlog group commit. If 0, one will be generated.
[in]	cont	the object used to wait

Returns

the operation status

Return values

0	OK
!=0	Error

The original_commit_timestamp for this GTID will be different for each member that generated this View_change_event.

is_unique()

bool Certification_handler::is_unique ( )

overridevirtual

This method identifies the handler as being unique.

An handler that is defined as unique is an handler that cannot be used more than once in a pipeline. Such tasks as certification and event application can only be done once. Unique handlers are also the only that, by being one of a kind, can be extracted during the pipeline life allowing dynamic changes to them.

Returns

if the handler is the a unique handler

Return values

true	is a unique handler
false	is a repeatable handler

Implements Event_handler.

log_view_change_event_in_order()

int Certification_handler::log_view_change_event_in_order ( Pipeline_event *  view_pevent, Continuation *  cont  )

private

Try to log a view change event waiting for local certified transactions to finish.

Parameters

[in]	view_pevent	the event to be injected
[in]	cont	the object used to wait

Returns

the operation status

Return values

0	OK
!=0	Error

Create a transactional block for the View change log event GTID BEGIN VCLE COMMIT

reset_transaction_context()

void Certification_handler::reset_transaction_context ( )

private

Reset transaction context.

set_certification_info()

int Certification_handler::set_certification_info

(

std::map< std::string, std::string > *

cert_info

)

set_transaction_context()

int Certification_handler::set_transaction_context ( Pipeline_event *  pevent )

private

Set transaction context for next event handler.

Parameters

[in]

pevent

Pipeline event that wraps Transaction_context_log_event.

Returns

Operation status

Return values

0	OK
!=0	Error

terminate()

int Certification_handler::terminate ( )

overridevirtual

Terminate the execution as defined in the handler implementation.

Implements Event_handler.

Member Data Documentation

applier_module_thd

THD* Certification_handler::applier_module_thd

private

cert_module

Certifier* Certification_handler::cert_module

private

group_sidno

rpl_sidno Certification_handler::group_sidno

private

pending_view_change_events_waiting_for_consistent_transactions

std::list<std::unique_ptr<View_change_stored_info> > Certification_handler::pending_view_change_events_waiting_for_consistent_transactions

private

All the VC events pending application due to consistent transactions.

transaction_context_packet

Data_packet* Certification_handler::transaction_context_packet

private

transaction_context_pevent

Pipeline_event* Certification_handler::transaction_context_pevent

private

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

• plugin/group_replication/include/handlers/certification_handler.h
• plugin/group_replication/src/handlers/certification_handler.cc