Esa Korhonen 45da5a08d9 MXS-1845 Cleanup monitor backend updating
Now detects errors and prints them.
2018-05-18 13:48:08 +03:00

261 lines
10 KiB
C++

#pragma once
/*
* Copyright (c) 2016 MariaDB Corporation Ab
*
* Use of this software is governed by the Business Source License included
* in the LICENSE.TXT file and at www.mariadb.com/bsl11.
*
* Change Date: 2020-01-01
*
* On the date above, in accordance with the Business Source License, use
* of this software will be governed by version 2 or later of the General
* Public License.
*/
#include "mariadbmon_common.hh"
#include <string>
#include <tr1/unordered_map>
#include <vector>
#include <maxscale/monitor.hh>
#include <maxscale/thread.h>
#include "mariadbserver.hh"
extern const char * const CN_AUTO_FAILOVER;
extern const char * const CN_PROMOTION_SQL_FILE;
extern const char * const CN_DEMOTION_SQL_FILE;
class MariaDBMonitor;
// Map of base struct to MariaDBServer. Does not own the server objects. May not be needed at the end.
typedef std::tr1::unordered_map<MXS_MONITORED_SERVER*, MariaDBServer*> ServerInfoMap;
// Server pointer array
typedef std::vector<MariaDBServer*> ServerArray;
// MariaDB Monitor instance data
class MariaDBMonitor : public MXS_MONITOR_INSTANCE
{
private:
MariaDBMonitor(const MariaDBMonitor&);
MariaDBMonitor& operator = (const MariaDBMonitor&);
public:
// TODO: Once done refactoring, see which of these can be moved to private.
/**
* Print diagnostics.
*
* @param dcb DCB to print to
*/
void diagnostics(DCB *dcb) const;
/**
* Print diagnostics to json object.
*
* @return Diagnostics messages
*/
json_t* diagnostics_json() const;
/**
* Runs the main monitor loop. Called from the static monitorMain()-function.
*/
void main_loop();
/**
* Create the monitor instance and return the instance data.
*
* @param monitor General monitor data
* @return A pointer to MariaDBMonitor specific data.
*/
static MariaDBMonitor* create(MXS_MONITOR *monitor);
/**
* Start the monitor instance.
* This function creates a thread to execute the monitoring.
*
* @param params Configuration parameters
* @return True, if the monitor could be started, false otherwise.
*/
bool start(const MXS_CONFIG_PARAMETER* params);
/**
* Destroyes aka deletes the instance.
*
* @param monitor The instance to be finished.
*/
static void destroy(MariaDBMonitor* monitor);
/**
* Stop the monitor. Waits until monitor has stopped.
*/
bool stop();
/**
* Handle switchover
*
* @new_master The specified new master
* @current_master The specified current master. If NULL, monitor will autoselect.
* @output Pointer where to place output object
*
* @return True, if switchover was performed, false otherwise.
*/
bool manual_switchover(SERVER* new_master, SERVER* current_master, json_t** error_out);
/**
* Perform user-activated failover.
*
* @param output Json error output
* @return True on success
*/
bool manual_failover(json_t** output);
/**
* Perform user-activated rejoin
*
* @param rejoin_server Server to join
* @param output Json error output
* @return True on success
*/
bool manual_rejoin(SERVER* rejoin_server, json_t** output);
private:
MXS_MONITOR* m_monitor_base; /**< Generic monitor object */
THREAD m_thread; /**< Monitor thread */
unsigned long m_id; /**< Monitor ID */
volatile bool m_keep_running; /**< Should monitor main loop keep running? */
volatile int m_status; /**< Monitor status */
ServerArray m_servers; /**< Servers of the monitor */
ServerInfoMap m_server_info; /**< Map from server base struct to MariaDBServer */
// Values updated by monitor
MariaDBServer* m_master; /**< Master server for Master/Slave replication */
int64_t m_master_gtid_domain; /**< gtid_domain_id most recently seen on the master */
std::string m_external_master_host; /**< External master host, for fail/switchover */
int m_external_master_port; /**< External master port */
// Replication topology detection settings
bool m_allow_cluster_recovery; /**< Allow failed servers to rejoin the cluster */
bool m_detect_replication_lag; /**< Monitor flag for MySQL replication heartbeat */
bool m_detect_multimaster; /**< Detect and handle multi-master topologies */
bool m_detect_stale_master; /**< Monitor flag for MySQL replication Stale Master detection */
bool m_detect_stale_slave; /**< Monitor flag for MySQL replication Stale Slave detection */
bool m_detect_standalone_master; /**< If standalone master are detected */
bool m_ignore_external_masters; /**< Ignore masters outside of the monitor configuration */
bool m_mysql51_replication; /**< Use MySQL 5.1 replication */
// Failover, switchover and rejoin settings
bool m_auto_failover; /**< Is automatic master failover is enabled? */
bool m_auto_rejoin; /**< Is automatic rejoin enabled? */
int m_failcount; /**< Numer of cycles master must be down before auto-failover begins */
std::string m_replication_user; /**< Replication user for CHANGE MASTER TO-commands */
std::string m_replication_password; /**< Replication password for CHANGE MASTER TO-commands */
uint32_t m_failover_timeout; /**< Time limit in seconds for master failover */
uint32_t m_switchover_timeout; /**< Time limit in seconds for master switchover */
bool m_verify_master_failure; /**< Is master failure is verified via slaves? */
int m_master_failure_timeout; /**< Master failure verification (via slaves) time in seconds */
ServerArray m_excluded_servers; /**< Servers banned for master promotion during auto-failover or
* autoselect switchover. */
std::string m_promote_sql_file; /**< File with sql commands which are ran to a server being promoted. */
std::string m_demote_sql_file; /**< File with sql commands which are ran to a server being demoted. */
// Other settings
std::string m_script; /**< Script to call when state changes occur on servers */
uint64_t m_events; /**< enabled events */
bool m_warn_set_standalone_master; /**< Log a warning when setting standalone master */
enum slave_down_setting_t
{
ACCEPT_DOWN,
REJECT_DOWN
};
// Base methods
MariaDBMonitor(MXS_MONITOR* monitor_base);
~MariaDBMonitor();
void reset_server_info();
void clear_server_info();
bool load_config_params(const MXS_CONFIG_PARAMETER* params);
bool set_replication_credentials(const MXS_CONFIG_PARAMETER* params);
MariaDBServer* get_server_info(MXS_MONITORED_SERVER* db);
// Cluster discovery and status assignment methods
MariaDBServer* find_root_master();
MXS_MONITORED_SERVER* get_replication_tree();
MXS_MONITORED_SERVER* build_mysql51_replication_tree();
void find_graph_cycles();
void update_server_states(MariaDBServer& db_server, MariaDBServer* root_master);
bool standalone_master_required();
bool set_standalone_master();
void assign_relay_master(MariaDBServer& serv_info);
void log_master_changes(MariaDBServer* root_master, int* log_no_master);
void update_gtid_domain();
void update_external_master();
void set_master_heartbeat(MariaDBServer*);
void set_slave_heartbeat(MariaDBServer*);
void measure_replication_lag(MariaDBServer* root_master);
void check_maxscale_schema_replication();
MXS_MONITORED_SERVER* getServerByNodeId(long);
MXS_MONITORED_SERVER* getSlaveOfNodeId(long, slave_down_setting_t);
// Switchover methods
bool switchover_check(SERVER* new_master, SERVER* current_master,
MariaDBServer** new_master_out, MariaDBServer** current_master_out,
json_t** error_out);
bool switchover_check_new(const MXS_MONITORED_SERVER* monitored_server, json_t** error);
bool switchover_check_current(const MXS_MONITORED_SERVER* suggested_curr_master,
json_t** error_out) const;
bool do_switchover(MariaDBServer** current_master, MariaDBServer** new_master, json_t** err_out);
bool switchover_check_preferred_master(MariaDBServer* preferred, json_t** err_out);
bool switchover_demote_master(MariaDBServer* current_master,
json_t** err_out);
bool switchover_wait_slaves_catchup(const ServerArray& slaves, const GtidList& gtid, int total_timeout,
json_t** err_out);
bool switchover_start_slave(MariaDBServer* old_master, MariaDBServer* new_master);
// Failover methods
bool handle_auto_failover();
bool failover_not_possible();
bool slave_receiving_events();
bool failover_check(json_t** error_out);
bool do_failover(json_t** err_out);
// Rejoin methods
bool cluster_can_be_joined();
void handle_auto_rejoin();
bool get_joinable_servers(ServerArray* output);
bool server_is_rejoin_suspect(MariaDBServer* rejoin_cand, json_t** output);
uint32_t do_rejoin(const ServerArray& joinable_servers, json_t** output);
// Methods common to failover/switchover/rejoin
MariaDBServer* select_new_master(ServerArray* slaves_out, json_t** err_out);
bool server_is_excluded(const MariaDBServer* server);
bool is_candidate_better(const MariaDBServer* current_best, const MariaDBServer* candidate,
uint32_t gtid_domain);
bool promote_new_master(MariaDBServer* new_master, json_t** err_out);
int redirect_slaves(MariaDBServer* new_master, const ServerArray& slaves,
ServerArray* redirected_slaves);
std::string generate_change_master_cmd(const std::string& master_host, int master_port);
bool start_external_replication(MariaDBServer* new_master, json_t** err_out);
bool wait_cluster_stabilization(MariaDBServer* new_master, const ServerArray& slaves,
int seconds_remaining);
void disable_setting(const char* setting);
void load_journal();
bool check_sql_files();
};
/**
* Generates a list of server names separated by ', '
*
* @param servers The servers
* @return Server names
*/
std::string monitored_servers_to_string(const ServerArray& servers);
/**
* Get MariaDB connection error strings from all the given servers, form one string.
*
* @param servers Servers with errors
* @return Concatenated string.
*/
std::string get_connection_errors(const ServerArray& servers);