Information about unreachable destination candidates that is shared between plugin instances. More...

#include <unreachable_destinations_quarantine.h>

Classes
struct	Unreachable_destination_candidate
	Class representing a single entry (destination) in quarantined destination set. More...

Public Member Functions
void	init (std::chrono::seconds quarantine_interval, uint32_t qurantine_threshold)
	Initialize the unreachable destination candidate mechanism. More...

void	register_routing_callbacks (QuarantineRoutingCallbacks &&routing_callbacks)

void	unregister_routing_callbacks ()

void	register_route (const std::string &route_name)

bool	report_connection_result (const mysql_harness::TCPAddress &dest, bool success)
	Register the connection error or success to a given destination. More...

void	remove_destination_candidate_from_quarantine (const mysql_harness::TCPAddress &dest)
	Remove unreachable destination candidate from quarantine. More...

bool	is_quarantined (const mysql_harness::TCPAddress &dest)
	Query the quarantined destination candidates set and check if the given destination candidate is quarantined. More...

void	refresh_quarantine (const std::string &instance_name, const bool nodes_changed_on_md_refresh, const std::vector< AvailableDestination > &available_destinations)
	Refresh the quarantined destination candidates list on metadata refresh. More...

void	stop_quarantine ()
	Stop all async operations and clear the quarantine list. More...

Private Member Functions
void	quarantine_handler (const std::error_code &ec, const mysql_harness::TCPAddress &dest)
	Async handler responsible of periodic checks for destination candidate availability. More...

void	add_destination_candidate_to_quarantine (const mysql_harness::TCPAddress &dest)

void	stop_socket_acceptors_on_all_nodes_quarantined ()
	Go through all routing instances and check if there are routing plugins which have all destination candidates added to quarantine, if so lets close the listening socket of such routing instances. More...

std::vector< std::string >	get_referencing_routing_instances (const mysql_harness::TCPAddress &destination)
	For a given destination get names of all routing instances that references it. More...

void	update_destinations_state (const AllowedNodes &destination_list)
	On metadata refresh we got a destination candidates list that is reported to be available (from the metadata perspective). More...

void	drop_stray_destinations (const std::string &instance_name, const AllowedNodes &routing_new_destinations)
	If destination list of a routing instance has changed it is possible that some destinations are no longer referenced by any routing instance. More...

Private Attributes
std::chrono::milliseconds	kQuarantinedConnectTimeout {1000}

std::chrono::seconds	quarantine_interval_ {1}

uint32_t	quarantine_threshold_ {1}

net::io_context &	io_ctx_ = IoComponent::get_instance().io_context()

std::mutex	quarantine_mutex_

std::vector< std::shared_ptr< Unreachable_destination_candidate > >	quarantined_destination_candidates_

std::map< mysql_harness::TCPAddress, uint32_t >	destination_errors_

std::mutex	destination_errors_mutex_

std::mutex	unreachable_destinations_init_mutex_

std::mutex	routing_instances_mutex_

std::vector< std::string >	routing_instances_

std::atomic< bool >	stopped_ {false}

std::atomic< size_t >	quarantined_dest_counter_ {0}
	number of quarantined destinations More...

std::condition_variable	quarantine_empty_cond_

std::mutex	quarantine_empty_cond_m_

QuarantineRoutingCallbacks	routing_callbacks_

Detailed Description

Information about unreachable destination candidates that is shared between plugin instances.

Quarantined destinations will not be used for routing purposes. Each unreachable destination candidate is periodically probed for availability and removed from the unreachable destination candidate set if it became available.

Member Function Documentation

◆ add_destination_candidate_to_quarantine()

void UnreachableDestinationsQuarantine::add_destination_candidate_to_quarantine ( const mysql_harness::TCPAddress & dest )

private

◆ drop_stray_destinations()

void UnreachableDestinationsQuarantine::drop_stray_destinations	(	const std::string &	instance_name,
		const AllowedNodes &	routing_new_destinations
	)

private

If destination list of a routing instance has changed it is possible that some destinations are no longer referenced by any routing instance.

In that case we should scan the quarantine list and remove those destinations.

Parameters

[in]	instance_name	Routing instance name that got destination candidates list update.
[in]	routing_new_destinations	List of new destination candidates for the given routing instance.

◆ get_referencing_routing_instances()

std::vector< std::string > UnreachableDestinationsQuarantine::get_referencing_routing_instances ( const mysql_harness::TCPAddress & destination )

private

For a given destination get names of all routing instances that references it.

Parameters

[in] destination Destination candidate address.

Returns: List of referencing routing instance names

◆ init()

void UnreachableDestinationsQuarantine::init	(	std::chrono::seconds	quarantine_interval,
		uint32_t	qurantine_threshold
	)

Initialize the unreachable destination candidate mechanism.

It will set up:

routing plugin instances callbacks used for probing/updating the unreachable destinations
harness context variable used for starting/stopping the routing listening sockets

quarantine_refresh_interval Used for unreachable destination candidates availability checks.

Parameters

[in]	quarantine_interval	The interval in seconds used for checking the health (connectivity) of the quarantined destinations.
[in]	qurantine_threshold	Number of consecutive reported failed connections to the destination until it gets quarantined.

◆ is_quarantined()

bool UnreachableDestinationsQuarantine::is_quarantined ( const mysql_harness::TCPAddress & dest )

Query the quarantined destination candidates set and check if the given destination candidate is quarantined.

Parameters

[in] dest Destination candidate address.

Returns: true if the destination candidate is quarantined, false otherwise.

◆ quarantine_handler()

void UnreachableDestinationsQuarantine::quarantine_handler	(	const std::error_code &	ec,
		const mysql_harness::TCPAddress &	dest
	)

private

Async handler responsible of periodic checks for destination candidate availability.

Parameters

[in]	ec	Result of async operation.
[in]	dest	Destination candidate address.

◆ refresh_quarantine()

void UnreachableDestinationsQuarantine::refresh_quarantine	(	const std::string &	instance_name,
		const bool	nodes_changed_on_md_refresh,
		const std::vector< AvailableDestination > &	available_destinations
	)

Refresh the quarantined destination candidates list on metadata refresh.

1) if the destination candidates list got updated we have to go through the quarantined destinations and check if there are still routing plugins that references them. 2) for each destination returned in the metadata (which is available from the md perspective) check if it is still unreachable and should be quarantined.

Parameters

[in]	instance_name	Routing plugin instance name.
[in]	nodes_changed_on_md_refresh	Information if the destination candidates have been updated for the given routing plugin.
[in]	available_destinations	List of destination candidates that are available for the given routing plugin after metadata refresh.

◆ register_route()

void UnreachableDestinationsQuarantine::register_route ( const std::string & route_name )

◆ register_routing_callbacks()

void UnreachableDestinationsQuarantine::register_routing_callbacks ( QuarantineRoutingCallbacks && routing_callbacks )

◆ remove_destination_candidate_from_quarantine()

void UnreachableDestinationsQuarantine::remove_destination_candidate_from_quarantine ( const mysql_harness::TCPAddress & dest )

Remove unreachable destination candidate from quarantine.

Parameters

[in] dest Unreachable destination candidate address.

◆ report_connection_result()

bool UnreachableDestinationsQuarantine::report_connection_result	(	const mysql_harness::TCPAddress &	dest,
		bool	success
	)

Register the connection error or success to a given destination.

If registering a success it will set the number of reported errors to a given connection to 0.

If registering a failure it will increment the number of reported failed connections to the destination. If the number reached the quarantine_threshold the destination will be added to the quarantine. If the destination candidate is not quarantine yet it will starting the async handler for it, otherwise it will just update the referencing plugins list.

Parameters

[in]	dest	Reported destination address.
[in]	success	Indicates if the reported connection result is success of failure.

Returns: true if the destination got added to the quarantine, false otherwise

◆ stop_quarantine()

void UnreachableDestinationsQuarantine::stop_quarantine ( )

Stop all async operations and clear the quarantine list.

◆ stop_socket_acceptors_on_all_nodes_quarantined()

void UnreachableDestinationsQuarantine::stop_socket_acceptors_on_all_nodes_quarantined ( )

private

Go through all routing instances and check if there are routing plugins which have all destination candidates added to quarantine, if so lets close the listening socket of such routing instances.

◆ unregister_routing_callbacks()

void UnreachableDestinationsQuarantine::unregister_routing_callbacks ( )

◆ update_destinations_state()

void UnreachableDestinationsQuarantine::update_destinations_state ( const AllowedNodes & destination_list )

private

On metadata refresh we got a destination candidates list that is reported to be available (from the metadata perspective).

Go through this list and check if any of the destination candidate is quarantined, if so verify if it is still unreachable and should be kept in quarantine.

Parameters

[in] destination_list Destination candidates reported to be available.

Member Data Documentation

◆ destination_errors_

std::map<mysql_harness::TCPAddress, uint32_t> UnreachableDestinationsQuarantine::destination_errors_

private

◆ destination_errors_mutex_

std::mutex UnreachableDestinationsQuarantine::destination_errors_mutex_

private

◆ io_ctx_

net::io_context& UnreachableDestinationsQuarantine::io_ctx_ = IoComponent::get_instance().io_context()

private

◆ kQuarantinedConnectTimeout

std::chrono::milliseconds UnreachableDestinationsQuarantine::kQuarantinedConnectTimeout {1000}

private

◆ quarantine_empty_cond_

std::condition_variable UnreachableDestinationsQuarantine::quarantine_empty_cond_

private

◆ quarantine_empty_cond_m_

std::mutex UnreachableDestinationsQuarantine::quarantine_empty_cond_m_

private

◆ quarantine_interval_

std::chrono::seconds UnreachableDestinationsQuarantine::quarantine_interval_ {1}

private

◆ quarantine_mutex_

std::mutex UnreachableDestinationsQuarantine::quarantine_mutex_

private

◆ quarantine_threshold_

uint32_t UnreachableDestinationsQuarantine::quarantine_threshold_ {1}

private

◆ quarantined_dest_counter_

std::atomic<size_t> UnreachableDestinationsQuarantine::quarantined_dest_counter_ {0}

private

number of quarantined destinations

◆ quarantined_destination_candidates_

std::vector<std::shared_ptr<Unreachable_destination_candidate> > UnreachableDestinationsQuarantine::quarantined_destination_candidates_

private

◆ routing_callbacks_

QuarantineRoutingCallbacks UnreachableDestinationsQuarantine::routing_callbacks_

private

◆ routing_instances_

std::vector<std::string> UnreachableDestinationsQuarantine::routing_instances_

private

◆ routing_instances_mutex_

std::mutex UnreachableDestinationsQuarantine::routing_instances_mutex_

private

◆ stopped_

std::atomic<bool> UnreachableDestinationsQuarantine::stopped_ {false}

private

◆ unreachable_destinations_init_mutex_

std::mutex UnreachableDestinationsQuarantine::unreachable_destinations_init_mutex_

private

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

router/src/destination_status/src/unreachable_destinations_quarantine.h
router/src/destination_status/src/unreachable_destinations_quarantine.cc

Classes

Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Member Function Documentation

◆ add_destination_candidate_to_quarantine()

◆ drop_stray_destinations()

◆ get_referencing_routing_instances()

◆ init()

◆ is_quarantined()

◆ quarantine_handler()

◆ refresh_quarantine()

◆ register_route()

◆ register_routing_callbacks()

◆ remove_destination_candidate_from_quarantine()

◆ report_connection_result()

◆ stop_quarantine()

◆ stop_socket_acceptors_on_all_nodes_quarantined()

◆ unregister_routing_callbacks()

◆ update_destinations_state()

Member Data Documentation

◆ destination_errors_

◆ destination_errors_mutex_

◆ io_ctx_

◆ kQuarantinedConnectTimeout

◆ quarantine_empty_cond_

◆ quarantine_empty_cond_m_

◆ quarantine_interval_

◆ quarantine_mutex_

◆ quarantine_threshold_

◆ quarantined_dest_counter_

◆ quarantined_destination_candidates_

◆ routing_callbacks_

◆ routing_instances_

◆ routing_instances_mutex_

◆ stopped_

◆ unreachable_destinations_init_mutex_