The MetadataCache manages cached information fetched from the MySQL Server. More...

#include <metadata_cache.h>

Inheritance diagram for MetadataCache:

Classes
struct	RestAuthData

struct	Stats

Public Member Functions
	MetadataCache (const unsigned router_id, const std::string &clusterset_id, const std::vector< mysql_harness::TCPAddress > &metadata_servers, std::shared_ptr< MetaData > cluster_metadata, const metadata_cache::MetadataCacheTTLConfig &ttl_config, const mysqlrouter::SSLOptions &ssl_options, const mysqlrouter::TargetCluster &target_cluster, const metadata_cache::RouterAttributes &router_attributes, size_t thread_stack_size=mysql_harness::kDefaultStackSizeInKiloBytes, bool use_cluster_notifications=false)
	Initialize a connection to the MySQL Metadata server. More...

	~MetadataCache () override

void	start ()
	Starts the Metadata Cache. More...

void	stop () noexcept
	Stops the Metadata Cache. More...

metadata_cache::cluster_nodes_list_t	get_cluster_nodes ()
	Returns list of managed servers in a cluster. More...

metadata_cache::ClusterTopology	get_cluster_topology ()
	Returns object containing current Cluster Topology. More...

bool	wait_primary_failover (const std::string &server_uuid, const std::chrono::seconds &timeout)
	Wait until cluster PRIMARY changes. More...

void	refresh_thread ()
	refresh cluster information More...

void	add_state_listener (metadata_cache::ClusterStateListenerInterface *listener) override
	Register observer that is notified when there is a change in the cluster nodes setup/state discovered. More...

void	remove_state_listener (metadata_cache::ClusterStateListenerInterface *listener) override
	Unregister observer previously registered with add_state_listener() More...

void	add_acceptor_handler_listener (metadata_cache::AcceptorUpdateHandlerInterface *listener)
	Register observer that is notified when the state of listening socket acceptors should be updated on the next metadata refresh. More...

void	remove_acceptor_handler_listener (metadata_cache::AcceptorUpdateHandlerInterface *listener)
	Unregister observer previously registered with add_acceptor_handler_listener() More...

void	add_md_refresh_listener (metadata_cache::MetadataRefreshListenerInterface *listener)
	Register observer that is notified on each metadata refresh event. More...

void	remove_md_refresh_listener (metadata_cache::MetadataRefreshListenerInterface *listener)
	Unregister observer previously registered with add_md_refresh_listener() More...

metadata_cache::MetadataCacheAPIBase::RefreshStatus	refresh_status ()

std::chrono::milliseconds	ttl () const

mysqlrouter::TargetCluster	target_cluster () const

virtual mysqlrouter::ClusterType	cluster_type () const noexcept=0

std::vector< mysql_harness::TCPAddress >	metadata_servers ()

void	enable_fetch_auth_metadata ()

void	force_cache_update ()

void	check_auth_metadata_timers () const

std::pair< bool, MetaData::auth_credentials_t::mapped_type >	get_rest_user_auth_data (const std::string &user)

void	handle_sockets_acceptors_on_md_refresh ()
	Toggle socket acceptors state update on next metadata refresh. More...

bool	fetch_whole_topology () const

void	fetch_whole_topology (bool val)

Public Member Functions inherited from metadata_cache::ClusterStateNotifierInterface
	ClusterStateNotifierInterface ()=default

	ClusterStateNotifierInterface (const ClusterStateNotifierInterface &)=delete

ClusterStateNotifierInterface &	operator= (const ClusterStateNotifierInterface &)=delete

virtual	~ClusterStateNotifierInterface ()

Static Public Member Functions
static void *	run_thread (void *context)
	run refresh thread More...

Protected Member Functions
virtual bool	refresh (bool needs_writable_node)=0
	Refreshes the cache. More...

void	on_refresh_failed (bool terminated, bool md_servers_reachable=false)

void	on_refresh_succeeded (const metadata_cache::metadata_server_t &metadata_server)

void	on_instances_changed (const bool md_servers_reachable, const metadata_cache::ClusterTopology &cluster_topology, uint64_t view_id=0)

void	on_handle_sockets_acceptors ()
	Called when the listening sockets acceptors state should be updated but replicaset instances has not changed (in that case socket acceptors would be handled when calling on_instances_changed). More...

void	on_md_refresh (const bool cluster_nodes_changed, const metadata_cache::ClusterTopology &cluster_topology)
	Called on each metadata refresh. More...

void	on_refresh_requested ()

void	on_refresh_completed ()

bool	update_auth_cache ()

void	update_router_attributes ()

void	update_router_last_check_in ()

bool	needs_initial_attributes_update ()

bool	needs_last_check_in_update ()

Protected Attributes
metadata_cache::ClusterTopology	cluster_topology_

mysqlrouter::TargetCluster	target_cluster_

const std::string	clusterset_id_

metadata_cache::metadata_servers_list_t	metadata_servers_

metadata_cache::MetadataCacheTTLConfig	ttl_config_

mysqlrouter::SSLOptions	ssl_options_

unsigned	router_id_

Monitor< RestAuthData >	rest_auth_ {{}}

bool	auth_metadata_fetch_enabled_ {false}

std::shared_ptr< MetaData >	meta_data_

mysql_harness::MySQLRouterThread	refresh_thread_
	refresh thread facade More...

mysql_harness::MySQLRouterThread	notification_thread_
	notification thread facade More...

std::mutex	cache_refreshing_mutex_

std::mutex	metadata_servers_mutex_

std::atomic< bool >	terminated_ {false}

bool	refresh_requested_ {false}

bool	use_cluster_notifications_

std::condition_variable	refresh_wait_

std::mutex	refresh_wait_mtx_

std::condition_variable	refresh_completed_

std::mutex	refresh_completed_mtx_

std::mutex	cluster_instances_change_callbacks_mtx_

std::mutex	acceptor_handler_callbacks_mtx_

std::mutex	md_refresh_callbacks_mtx_

std::set< metadata_cache::ClusterStateListenerInterface * >	state_listeners_

std::set< metadata_cache::AcceptorUpdateHandlerInterface * >	acceptor_update_listeners_

std::set< metadata_cache::MetadataRefreshListenerInterface * >	md_refresh_listeners_

Monitor< Stats >	stats_ {{}}

bool	initial_attributes_update_done_ {false}

uint32_t	periodic_stats_update_counter_ {1}

std::chrono::steady_clock::time_point	last_periodic_stats_update_timestamp_

bool	ready_announced_ {false}

std::atomic< bool >	fetch_whole_topology_ {false}

std::atomic< bool >	trigger_acceptor_update_on_next_refresh_ {false}
	Flag indicating if socket acceptors state should be updated on next metadata refresh even if instance information has not changed. More...

metadata_cache::RouterAttributes	router_attributes_

Detailed Description

The MetadataCache manages cached information fetched from the MySQL Server.

Constructor & Destructor Documentation

◆ MetadataCache()

MetadataCache::MetadataCache	(	const unsigned	router_id,
		const std::string &	clusterset_id,
		const std::vector< mysql_harness::TCPAddress > &	metadata_servers,
		std::shared_ptr< MetaData >	cluster_metadata,
		const metadata_cache::MetadataCacheTTLConfig &	ttl_config,
		const mysqlrouter::SSLOptions &	ssl_options,
		const mysqlrouter::TargetCluster &	target_cluster,
		const metadata_cache::RouterAttributes &	router_attributes,
		size_t	thread_stack_size = `mysql_harness::kDefaultStackSizeInKiloBytes`,
		bool	use_cluster_notifications = `false`
	)

Initialize a connection to the MySQL Metadata server.

Parameters

router_id	id of the router in the cluster metadata
clusterset_id	UUID of the ClusterSet the Cluster belongs to (if bootstrapped as a ClusterSet, empty otherwise)
metadata_servers	The servers that store the metadata
cluster_metadata	metadata of the cluster
ttl_config	metadata TTL configuration
ssl_options	SSL related options for connection
target_cluster	object identifying the Cluster this operation refers to
router_attributes	Router attributes to be registered in the metadata
thread_stack_size	The maximum memory allocated for thread's stack
use_cluster_notifications	Flag indicating if the metadata cache should use GR notifications as an additional trigger for metadata refresh

◆ ~MetadataCache()

MetadataCache::~MetadataCache ( )

override

Member Function Documentation

◆ add_acceptor_handler_listener()

void MetadataCache::add_acceptor_handler_listener ( metadata_cache::AcceptorUpdateHandlerInterface * listener )

Register observer that is notified when the state of listening socket acceptors should be updated on the next metadata refresh.

Parameters

listener Observer object that is notified when replicaset nodes state is changed.

◆ add_md_refresh_listener()

void MetadataCache::add_md_refresh_listener ( metadata_cache::MetadataRefreshListenerInterface * listener )

Register observer that is notified on each metadata refresh event.

Parameters

listener Observer object that is notified on md refresh.

◆ add_state_listener()

void MetadataCache::add_state_listener ( metadata_cache::ClusterStateListenerInterface * listener )

overridevirtual

Register observer that is notified when there is a change in the cluster nodes setup/state discovered.

Parameters

listener Observer object that is notified when cluster nodes state is changed.

Implements metadata_cache::ClusterStateNotifierInterface.

◆ check_auth_metadata_timers()

void MetadataCache::check_auth_metadata_timers ( ) const

◆ cluster_type()

virtual mysqlrouter::ClusterType MetadataCache::cluster_type ( ) const

pure virtualnoexcept

Implemented in ARMetadataCache, and GRMetadataCache.

◆ enable_fetch_auth_metadata()

void MetadataCache::enable_fetch_auth_metadata ( )

inline

◆ fetch_whole_topology() [1/2]

bool MetadataCache::fetch_whole_topology ( ) const

inline

◆ fetch_whole_topology() [2/2]

void MetadataCache::fetch_whole_topology ( bool val )

◆ force_cache_update()

void MetadataCache::force_cache_update ( )

inline

◆ get_cluster_nodes()

metadata_cache::cluster_nodes_list_t MetadataCache::get_cluster_nodes ( )

Returns list of managed servers in a cluster.

Return a list of servers that are part of a cluster.

Returns: std::vector containing ManagedInstance objects

◆ get_cluster_topology()

metadata_cache::ClusterTopology MetadataCache::get_cluster_topology ( )

Returns object containing current Cluster Topology.

◆ get_rest_user_auth_data()

std::pair< bool, MetaData::auth_credentials_t::mapped_type > MetadataCache::get_rest_user_auth_data ( const std::string & user )

◆ handle_sockets_acceptors_on_md_refresh()

void MetadataCache::handle_sockets_acceptors_on_md_refresh ( )

inline

Toggle socket acceptors state update on next metadata refresh.

◆ metadata_servers()

std::vector< mysql_harness::TCPAddress > MetadataCache::metadata_servers ( )

◆ needs_initial_attributes_update()

bool MetadataCache::needs_initial_attributes_update ( )

protected

◆ needs_last_check_in_update()

bool MetadataCache::needs_last_check_in_update ( )

protected

◆ on_handle_sockets_acceptors()

void MetadataCache::on_handle_sockets_acceptors ( )

protected

Called when the listening sockets acceptors state should be updated but replicaset instances has not changed (in that case socket acceptors would be handled when calling on_instances_changed).

◆ on_instances_changed()

void MetadataCache::on_instances_changed	(	const bool	md_servers_reachable,
		const metadata_cache::ClusterTopology &	cluster_topology,
		uint64_t	view_id = `0`
	)

protected

◆ on_md_refresh()

void MetadataCache::on_md_refresh	(	const bool	cluster_nodes_changed,
		const metadata_cache::ClusterTopology &	cluster_topology
	)

protected

Called on each metadata refresh.

Parameters

[in]	cluster_nodes_changed	Information whether there was a change in instances reported by metadata refresh.
[in]	cluster_topology	current cluster topology

◆ on_refresh_completed()

void MetadataCache::on_refresh_completed ( )

protected

◆ on_refresh_failed()

void MetadataCache::on_refresh_failed	(	bool	terminated,
		bool	md_servers_reachable = `false`
	)

protected

◆ on_refresh_requested()

void MetadataCache::on_refresh_requested ( )

protected

◆ on_refresh_succeeded()

void MetadataCache::on_refresh_succeeded ( const metadata_cache::metadata_server_t & metadata_server )

protected

◆ refresh()

virtual bool MetadataCache::refresh ( bool needs_writable_node )

protectedpure virtual

Refreshes the cache.

Implemented in ARMetadataCache, and GRMetadataCache.

◆ refresh_status()

metadata_cache::MetadataCacheAPIBase::RefreshStatus MetadataCache::refresh_status ( )

inline

◆ refresh_thread()

void MetadataCache::refresh_thread ( )

refresh cluster information

◆ remove_acceptor_handler_listener()

void MetadataCache::remove_acceptor_handler_listener ( metadata_cache::AcceptorUpdateHandlerInterface * listener )

Unregister observer previously registered with add_acceptor_handler_listener()

Parameters

listener Observer object that should be unregistered.

◆ remove_md_refresh_listener()

void MetadataCache::remove_md_refresh_listener ( metadata_cache::MetadataRefreshListenerInterface * listener )

Unregister observer previously registered with add_md_refresh_listener()

Parameters

listener Observer object that should be unregistered.

◆ remove_state_listener()

void MetadataCache::remove_state_listener ( metadata_cache::ClusterStateListenerInterface * listener )

overridevirtual

Unregister observer previously registered with add_state_listener()

Parameters

listener Observer object that should be unregistered.

Implements metadata_cache::ClusterStateNotifierInterface.

◆ run_thread()

void * MetadataCache::run_thread ( void * context )

static

run refresh thread

◆ start()

void MetadataCache::start ( )

Starts the Metadata Cache.

Connect to the metadata servers and refresh the metadata information in the cache.

Starts the Metadata Cache and launch thread.

◆ stop()

void MetadataCache::stop ( )

noexcept

Stops the Metadata Cache.

Stop the refresh thread.

Stops the Metadata Cache and the launch thread.

◆ target_cluster()

mysqlrouter::TargetCluster MetadataCache::target_cluster ( ) const

inline

◆ ttl()

std::chrono::milliseconds MetadataCache::ttl ( ) const

inline

◆ update_auth_cache()

bool MetadataCache::update_auth_cache ( )

protected

◆ update_router_attributes()

void MetadataCache::update_router_attributes ( )

protected

◆ update_router_last_check_in()

void MetadataCache::update_router_last_check_in ( )

protected

◆ wait_primary_failover()

bool MetadataCache::wait_primary_failover	(	const std::string &	server_uuid,
		const std::chrono::seconds &	timeout
	)

Wait until cluster PRIMARY changes.

wait until a change of the PRIMARY is noticed

leave early if

'timeout' expires
process shutdown is requested

function has to handle two scenarios:

connection to PRIMARY fails because:

PRIMARY died and group relects a new member
network to PRIMARY lost, but GR sees no fault and PRIMARY does not change.

Therefore, if the connection to PRIMARY fails, wait for change of the membership or timeout, whatever happens earlier.

Parameters

server_uuid	server-uuid of the PRIMARY that we failed to connect
timeout	- amount of time to wait for a failover

Returns: true if a primary member exists

Member Data Documentation

◆ acceptor_handler_callbacks_mtx_

std::mutex MetadataCache::acceptor_handler_callbacks_mtx_

protected

◆ acceptor_update_listeners_

std::set<metadata_cache::AcceptorUpdateHandlerInterface *> MetadataCache::acceptor_update_listeners_

protected

◆ auth_metadata_fetch_enabled_

bool MetadataCache::auth_metadata_fetch_enabled_ {false}

protected

◆ cache_refreshing_mutex_

std::mutex MetadataCache::cache_refreshing_mutex_

protected

◆ cluster_instances_change_callbacks_mtx_

std::mutex MetadataCache::cluster_instances_change_callbacks_mtx_

protected

◆ cluster_topology_

metadata_cache::ClusterTopology MetadataCache::cluster_topology_

protected

◆ clusterset_id_

const std::string MetadataCache::clusterset_id_

protected

◆ fetch_whole_topology_

std::atomic<bool> MetadataCache::fetch_whole_topology_ {false}

protected

◆ initial_attributes_update_done_

bool MetadataCache::initial_attributes_update_done_ {false}

protected

◆ last_periodic_stats_update_timestamp_

std::chrono::steady_clock::time_point MetadataCache::last_periodic_stats_update_timestamp_

protected

Initial value:

{

std::chrono::steady_clock::now()}

◆ md_refresh_callbacks_mtx_

std::mutex MetadataCache::md_refresh_callbacks_mtx_

protected

◆ md_refresh_listeners_

std::set<metadata_cache::MetadataRefreshListenerInterface *> MetadataCache::md_refresh_listeners_

protected

◆ meta_data_

std::shared_ptr<MetaData> MetadataCache::meta_data_

protected

◆ metadata_servers_

metadata_cache::metadata_servers_list_t MetadataCache::metadata_servers_

protected

◆ metadata_servers_mutex_

std::mutex MetadataCache::metadata_servers_mutex_

protected

◆ notification_thread_

mysql_harness::MySQLRouterThread MetadataCache::notification_thread_

protected

notification thread facade

◆ periodic_stats_update_counter_

uint32_t MetadataCache::periodic_stats_update_counter_ {1}

protected

◆ ready_announced_

bool MetadataCache::ready_announced_ {false}

protected

◆ refresh_completed_

std::condition_variable MetadataCache::refresh_completed_

protected

◆ refresh_completed_mtx_

std::mutex MetadataCache::refresh_completed_mtx_

protected

◆ refresh_requested_

bool MetadataCache::refresh_requested_ {false}

protected

◆ refresh_thread_

mysql_harness::MySQLRouterThread MetadataCache::refresh_thread_

protected

refresh thread facade

◆ refresh_wait_

std::condition_variable MetadataCache::refresh_wait_

protected

◆ refresh_wait_mtx_

std::mutex MetadataCache::refresh_wait_mtx_

protected

◆ rest_auth_

Monitor<RestAuthData> MetadataCache::rest_auth_ {{}}

protected

◆ router_attributes_

metadata_cache::RouterAttributes MetadataCache::router_attributes_

protected

◆ router_id_

unsigned MetadataCache::router_id_

protected

◆ ssl_options_

mysqlrouter::SSLOptions MetadataCache::ssl_options_

protected

◆ state_listeners_

std::set<metadata_cache::ClusterStateListenerInterface *> MetadataCache::state_listeners_

protected

◆ stats_

Monitor<Stats> MetadataCache::stats_ {{}}

protected

◆ target_cluster_

mysqlrouter::TargetCluster MetadataCache::target_cluster_

protected

◆ terminated_

std::atomic<bool> MetadataCache::terminated_ {false}

protected

◆ trigger_acceptor_update_on_next_refresh_

std::atomic<bool> MetadataCache::trigger_acceptor_update_on_next_refresh_ {false}

protected

Flag indicating if socket acceptors state should be updated on next metadata refresh even if instance information has not changed.

◆ ttl_config_

metadata_cache::MetadataCacheTTLConfig MetadataCache::ttl_config_

protected

◆ use_cluster_notifications_

bool MetadataCache::use_cluster_notifications_

protected

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

router/src/metadata_cache/src/metadata_cache.h
router/src/metadata_cache/src/metadata_cache.cc

Classes

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ MetadataCache()

◆ ~MetadataCache()

Member Function Documentation

◆ add_acceptor_handler_listener()

◆ add_md_refresh_listener()

◆ add_state_listener()

◆ check_auth_metadata_timers()

◆ cluster_type()

◆ enable_fetch_auth_metadata()

◆ fetch_whole_topology() [1/2]

◆ fetch_whole_topology() [2/2]

◆ force_cache_update()

◆ get_cluster_nodes()

◆ get_cluster_topology()

◆ get_rest_user_auth_data()

◆ handle_sockets_acceptors_on_md_refresh()

◆ metadata_servers()

◆ needs_initial_attributes_update()

◆ needs_last_check_in_update()

◆ on_handle_sockets_acceptors()

◆ on_instances_changed()

◆ on_md_refresh()

◆ on_refresh_completed()

◆ on_refresh_failed()

◆ on_refresh_requested()

◆ on_refresh_succeeded()

◆ refresh()

◆ refresh_status()

◆ refresh_thread()

◆ remove_acceptor_handler_listener()

◆ remove_md_refresh_listener()

◆ remove_state_listener()

◆ run_thread()

◆ start()

◆ stop()

◆ target_cluster()

◆ ttl()

◆ update_auth_cache()

◆ update_router_attributes()

◆ update_router_last_check_in()

◆ wait_primary_failover()

Member Data Documentation

◆ acceptor_handler_callbacks_mtx_

◆ acceptor_update_listeners_

◆ auth_metadata_fetch_enabled_

◆ cache_refreshing_mutex_

◆ cluster_instances_change_callbacks_mtx_

◆ cluster_topology_

◆ clusterset_id_

◆ fetch_whole_topology_

◆ initial_attributes_update_done_

◆ last_periodic_stats_update_timestamp_

◆ md_refresh_callbacks_mtx_

◆ md_refresh_listeners_

◆ meta_data_

◆ metadata_servers_

◆ metadata_servers_mutex_

◆ notification_thread_

◆ periodic_stats_update_counter_

◆ ready_announced_

◆ refresh_completed_

◆ refresh_completed_mtx_

◆ refresh_requested_

◆ refresh_thread_

◆ refresh_wait_

◆ refresh_wait_mtx_

◆ rest_auth_

◆ router_attributes_

◆ router_id_

◆ ssl_options_

◆ state_listeners_

◆ stats_

◆ target_cluster_